United States Court of Appeals
                    For the First Circuit


No. 16-2089

                   UNITED STATES OF AMERICA,

                           Appellee,

                              v.

                     JEFFRI DÁVILA-REYES,

                     Defendant, Appellant.

No. 16-2143

                   UNITED STATES OF AMERICA,

                           Appellee,

                              v.

                    JOSÉ D. REYES-VALDIVIA,

                     Defendant, Appellant.




         APPEALS FROM THE UNITED STATES DISTRICT COURT
                FOR THE DISTRICT OF PUERTO RICO

        [Hon. Francisco A. Besosa, U.S. District Judge]


                            Before

                      Howard, Chief Judge,
              Lipez and Thompson, Circuit Judges.
     Franco L. Pérez-Redondo, Research and Writing Specialist,
with whom Eric Alexander Vos, Federal Public Defender, Vivianne M.
Marrero, Assistant Federal Public Defender, and Liza L. Rosado-
Rodríguez, Research and Writing Specialist, were on brief, for
appellant José D. Reyes-Valdivia.

     Raymond L. Sánchez-Maceira on brief for appellant Jeffri
Dávila-Reyes.

     Thomas F. Klumper, Assistant United States Attorney, with
whom Rosa Emilia Rodríguez-Vélez, United States Attorney, Mariana
E. Bauzá-Almonte, Assistant United States Attorney, Chief,
Appellate Division, John A. Mathews II, Assistant United States
Attorney, and David C. Bornstein, Assistant United States
Attorney, were on brief, for appellee.


                        January 20, 2022
           LIPEZ, Circuit Judge.            These consolidated appeals arise

from the U.S. Coast Guard's interdiction of a small speed boat in

the western Caribbean Sea and the subsequent arrest and indictment

of the three men on board for drug trafficking under the Maritime

Drug Law Enforcement Act ("MDLEA"), 

.                       In a

motion to dismiss the indictment, appellants José Reyes-Valdivia

and Jeffri Dávila-Reyes challenged the constitutionality of the

MDLEA in multiple respects.            Most relevant here, they argued that

the   statute,    which     in    certain   circumstances       allows    U.S.   law

enforcement to arrest and prosecute foreign nationals for drug

crimes   committed    in     international       waters,      exceeds    Congress's

authority under Article I of the Constitution.                 The district court

denied the motion to dismiss.           Both appellants then pleaded guilty

pursuant to plea agreements in which each waived his right to

appeal if sentenced in accordance with his agreement's sentencing

recommendation provision.

           On     appeal,        appellants     renew   their     constitutional

objections to their prosecution.            In our original decision, we did

not reach appellants' "primary argument" -- that their prosecution

was unlawful because their vessel was not properly deemed stateless

-- on the ground that "our governing precedent concerning the

protective      principle        of   international     law    . . . permit[ted]

prosecution under the MDLEA even of foreigners on foreign vessels."

United States v. Dávila-Reyes, 

 (1st Cir. 2019)


                                        - 3 -
(withdrawn).1          That precedent, we concluded, required that we

affirm appellants' convictions.

               Appellants then petitioned for panel rehearing and en

banc review.          We held their requests in abeyance pending the en

banc       decision    in    another   drug-trafficking    case    involving   a

constitutional challenge to the MDLEA. See United States v. Aybar-

Ulloa, 

 (1st Cir. 2021) (en banc).              Subsequently, based

on our view that the decision in Aybar-Ulloa "diminished the force

of this circuit's precedent on the protective principle," we

concluded that it would no longer be appropriate to rely on that

principle to uphold appellants' convictions.              Order, Nos. 16-2089,

2143 (Mar. 17, 2021).             We therefore granted panel rehearing to

address appellants' constitutional challenge to their prosecution

under the MDLEA.

               We now hold that Congress exceeded its authority under

Article I of the Constitution in enacting § 70502(d)(1)(C) of the

MDLEA.      That provision expands the definition of a "vessel without

nationality" beyond the bounds of international law and thus

unconstitutionally           extends U.S. jurisdiction to         foreigners on

foreign vessels.            Hence, appellants' convictions must be vacated.



       The protective principle of international law "permits a
       1

nation 'to assert jurisdiction over a person whose conduct outside
the nation's territory threatens the nation's security.'" Dávila-
Reyes, 

 (quoting United States v. Cardales, 

 (1st Cir. 1999)).


                                        - 4 -
                                I.

          We draw the following facts primarily from appellants'

change of plea colloquies and the uncontested portions of their

Presentence Investigation Reports.    See United States v. Vélez-

Luciano, 

 (1st Cir. 2016).2       In October 2015,

while patrolling waters approximately 30 nautical miles southeast

of San Andrés Island, Colombia,3 U.S. Coast Guard officers observed

a small vessel4 moving at a high rate of speed.   When the occupants

of the vessel became aware of the Coast Guard boat nearby, they

began throwing packages and fuel barrels overboard.       The Coast

Guard officers approached the boat and began to question its

occupants, the two appellants and a third co-defendant.      Reyes-

Valdivia, as the "master"5 of the vessel, claimed Costa Rican


     2 We also draw some facts from statements by Coast Guard
officials that were submitted to the district court as attachments
to the government's Motion in Limine and Memorandum of Law in
Support of Jurisdiction. See United States v. Reyes-Valdivia, No.
3:15-cr-00721-FAB (D.P.R. Mar. 25, 2016), ECF No. 46.
     We note that all citations to the district court's electronic
docket in this case will hereafter be cited using the short-form
"Reyes-Valdivia, ECF No. __ (filing date)."
     3 Although part of Colombia, San Andrés Island is located off
the coast of Nicaragua.
     4 The government's Motion in Limine describes the vessel as a
35-foot "low profile, open hull, 'go-fast-type' vessel." Reyes-
Valdivia, ECF No. 46, at 3 (Mar. 25, 2016).
     5 The term "master" is synonymous with "captain." It is a
legal term of art meaning the person "to whom are committed the
government, care, and direction of the vessel and cargo."
Kennerson v. Jane R., Inc., 

 (S.D. Tex. 1967).
The statement of facts attached to Reyes-Valdivia's plea agreement


                              - 5 -
nationality for the vessel but did not provide any documentation

to support that claim.6

              The Coast Guard officers boarded and searched the vessel

pursuant to a provision of an agreement between the United States

and   Costa     Rica   "Concerning   Cooperation   to   Suppress   Illicit

Traffic."      See Reyes-Valdivia, ECF No. 46-2, at 1 (Mar. 25, 2016)

(Dep't of State Certification).          The officers did not find any

contraband, but a chemical test detected traces of cocaine.          Based

on that evidence, the Coast Guard detained the three men -- all

citizens of Costa Rica -- and took them to the U.S. Naval Base at

Guantánamo Bay, Cuba, and then eventually to Puerto Rico.          At some

point, the United States contacted the government of Costa Rica

requesting confirmation of the vessel's registry or nationality,

and Costa Rica subsequently responded that it could not confirm




does not identify him as the "master" of the vessel, see Reyes-
Valdivia, ECF No. 68, at 11 (Apr. 4, 2016), but a statement from
a Coast Guard officer reports that Reyes-Valdivia identified
himself as such, see 

 ECF No. 46-1, at 1 (Mar. 25, 2016)
(Statement of Officer Luis Rosado).
      6The Coast Guard reported that Reyes-Valdivia initially
stated that "there was no nationality for the vessel" before
asserting Costa Rican nationality. Reyes-Valdivia, ECF No. 46-1,
at 1 (Mar. 25, 2016) (Statement of Officer Luis Rosado). However,
this statement was not cited in the U.S. Department of State
Certification as a basis for identifying the vessel as stateless.
The Certification reported only that "[t]he master made a claim of
Costa Rican nationality for the go fast vessel." 

 ECF No. 46-
2, at 1 (Mar. 25, 2016). Nor was the statement included in the
government's version of the facts in the appellants' plea
agreements. See infra.


                                     - 6 -
the vessel's registry.          The United States thus determined that,

pursuant to § 70502(d)(1)(C) of the MDLEA, the boat was "without

nationality" and subject to U.S. jurisdiction.7

             All three defendants were charged with two counts of

trafficking cocaine in violation of the MDLEA.                  Reyes-Valdivia and

Dávila-Reyes     moved     to       dismiss   the        indictment    for    lack    of

jurisdiction,8        arguing          that        the      MDLEA,      particularly

§ 70502(d)(1)(C),        is     unconstitutional.               In     their     view,

§ 70502(d)(1)(C) exceeds Congress's authority under Article I of

the Constitution, and it violates the Due Process Clause of the

Fifth Amendment because it is unconstitutionally vague, subject to

arbitrary enforcement, and criminalizes conduct that has no nexus

with the United States.         The district court denied the motion.

             Reyes-Valdivia and Dávila-Reyes both subsequently agreed

to   plead   guilty   to      one    count    of    possession       with    intent   to

distribute five or more kilograms of cocaine in violation of the




      7Section 70502(c)(1)(A) of the MDLEA provides that "a vessel
without nationality" is "subject to the jurisdiction of the United
States."    

(c)(1)(A).      As explained below,
§ 70502(d)(1)(C) defines a "vessel without nationality" to include
any vessel "aboard which the master or individual in charge makes
a claim of registry and for which the claimed nation of registry
does not affirmatively and unequivocally assert that the vessel is
of its nationality." Id. § 70502(d)(1)(C).
      8Reyes-Valdivia filed the motion, and the district court
granted Dávila-Reyes's motion to join.


                                        - 7 -
MDLEA.    See 

(a)(1).9        Both men agreed to waive

appellate review if sentenced in accordance with the sentencing

recommendation provisions in their plea agreements.              Ultimately,

the district court sentenced Dávila-Reyes consistently with his

agreement (a 120-month term), but sentenced Reyes-Valdivia to a

term longer than proposed in his agreement (70 months instead of

57)   because   it   found   that   he    should   be   given   a   two-level

enhancement for being the "captain" of the vessel.              See U.S.S.G.

§ 2D1.1(b)(3)(C).

           Reyes-Valdivia's motion for reconsideration was denied.

Both Reyes-Valdivia and Dávila-Reyes then appealed.             We affirmed

their convictions on the basis that the protective principle

permitted their prosecution.

                                    II.

           As noted, this court's en banc decision in United States

v. Aybar-Ulloa led us to withdraw our prior opinion and reconsider

appellants' claims.     In Aybar-Ulloa, the en banc court held that

"international law accepts the criminal prosecution by the United

States of persons . . . who [are] seized by the United States while

trafficking cocaine on a stateless vessel on the high seas."              987




      9The third defendant also pleaded guilty to this count and
was sentenced to a 57-month term of imprisonment. He did not file
an appeal.


                                    - 8 -
F.3d at 3.10          In so holding, the court bypassed our circuit's

precedent on the protective principle, which could have provided

a straightforward basis for affirming the conviction, and instead

addressed a more complex issue of international law.                              Notably, the

en banc court did not achieve unanimity on the legal basis for

U.S. jurisdiction over foreign nationals apprehended on vessels

conceded to be stateless.                  See infra.           The choice of a non-

unanimous       analytical         path    over     reliance         on     the    protective

principle is one basis for our conclusion that Aybar-Ulloa weakened

our circuit's protective principle jurisprudence.

               In    addition,       statements        in     both    the     majority      and

concurring          opinions       in     Aybar-Ulloa         more     directly       suggest

skepticism about applying the protective principle to a foreign

vessel whose occupants are foreign nationals allegedly involved in

drug trafficking, at least absent acquiescence by the flag nation.

The majority observed that one of our primary precedents on the

protective principle -- United States v. Cardales, 

(1st    Cir.    1999)     --       "can    be   read     as    applying       only     to   the

circumstance         where     a    foreign       flag      nation        consents    to    the

application of United States law to persons found on that nation's

flagged vessel." Aybar-Ulloa, 

.                         In our prior opinion


        Generally, there is a consensus that "high seas" denotes
       10

areas outside any country's territorial waters. See, e.g., United
States v. Carvajal, 

 (D.D.C. 2013), aff'd
sub nom. United States v. Miranda, 

 (D.C. Cir. 2015).


                                            - 9 -
in this case, we assumed that appellants' vessel was Costa Rican,

as   they     had   asserted,    but     we     concluded    that     our   precedent

nonetheless required us to uphold their prosecution based on the

protective principle.         The Aybar-Ulloa majority's posited reading

of Cardales, however, would foreclose reliance on the protective

principle here because the record contains no consent from the

Costa Rican government to the prosecution.

              The Aybar-Ulloa concurring opinion aired an even broader

uncertainty about the protective principle.                  In describing Aybar-

Ulloa's       contentions,      the     concurrence         noted     the    long-ago

observation      by   then-Judge       Breyer    that   there    is    a    "'forceful

argument' against application of [the] protective principle to

encompass drug trafficking on the high seas."                   Id. at 15 (Barron,

J., concurring) (quoting United States v. Robinson, 

(1st Cir. 1988) (Breyer, J.)); see also 

 (referencing the

same skepticism about the protective principle with a citation to

Robinson).      Both Aybar-Ulloa opinions, then, caused the panel to

doubt its reliance on the protective principle to uphold Reyes-

Valdivia and Dávila-Reyes's prosecution under the MDLEA.                      See also

Aaron J. Casavant, In Defense of the U.S. Maritime Drug Law

Enforcement Act: A Justification for the Law's Extraterritorial

Reach,    8   Harv.   Nat'l     Sec.    J.    191,   213    (2017)     (noting    that

commentators have rejected the protective principle to support

MDLEA prosecutions, "positing that 'the cases that see the MDLEA


                                        - 10 -
as   an   exercise   of   protective   jurisdiction   fundamentally

misconceive the principle'" (quoting Eugene Kontorovich, Beyond

the Article I Horizon: Congress's Enumerated Powers and Universal

Jurisdiction Over Drug Crimes, 

, 1231 (2009)

(emphasis omitted))); but see 

 (noting "a circuit

split over whether the crime of maritime drug trafficking warrants

the use of the protective principle"); 

 (stating that

"the protective principle of international law is broad enough to

encompass maritime drug trafficking").

          Apart from any reference to the protective principle,

both Aybar-Ulloa opinions include statements indicating that the

prosecution of a foreign national seized on the high seas under

U.S. drug-trafficking laws would not be proper unless the targeted

activity and seizure occurred on a stateless vessel. The majority,

for example, concludes a passage on the reasonable expectations of

"those who set out in stateless vessels" by noting: "Simply put,

if a person intent on drug trafficking on the high seas wants to

be prosecuted in his own country should he be caught, he should

sail under that country's flag."   Aybar-Ulloa, 

.   The

majority subsequently describes its holding as limited "to vessels

flouting order and custom on the high seas by eschewing the

responsibilities and protections of the flag-state system."      

; see also 

 at 8 (quoting United States v. Furlong, 

 (1820), for the proposition that "the


                              - 11 -
distinction between foreign vessels and stateless vessels serves

to avoid 'offensive interference with the governments of other

nations'").      In the same vein, the concurring opinion in Aybar-

Ulloa notes the "fair amount of support" for the view that Congress

lacks authority under Article I's Define and Punish Clause "to

subject foreign nationals to our criminal laws" for acts occurring

on foreign vessels on the high seas.                Id. at 15 (Barron, J.,

concurring).11

           In sum, we see in Aybar-Ulloa multiple signals that the

majority   of    judges   on   our   court    do   not   view   the   protective

principle as supporting U.S. jurisdiction over drug-trafficking



     11 Elsewhere, the Aybar-Ulloa concurrence notes that "the
application of the MDLEA to Aybar[-Ulloa]'s conduct in this case"
-- i.e., conduct aboard a stateless vessel -- would likely be
consistent with international law,
           [e]ven if we were to assume that the law of
           nations places limits on Congress's power
           under the Define and Punish Clause to subject
           foreign nationals on foreign vessels in
           international waters to our domestic criminal
           laws, and even if we were to assume that the
           United States may not assert protective
           jurisdiction over drug trafficking merely
           because it occurs on stateless vessels in
           international waters, see Robinson, 

.

.    Although the Aybar-Ulloa concurrence does not
take a position on those hypotheticals, we view them -- and the
reiterated citation to Robinson -- to indicate a level of doubt
about the applicability of the protective principle, at a minimum,
to drug-trafficking activity by foreign nationals on foreign
vessels.


                                     - 12 -
activity conducted on the high seas by foreign nationals on foreign

vessels.12    Hence, in light of Aybar-Ulloa, we decline to rely on

the   protective   principle   to    uphold   appellants'   convictions.

Rather, the question we must answer is whether -- as the United

States claims -- appellants' vessel was properly deemed stateless,

bringing the vessel and its occupants within the scope of the

holding in Aybar-Ulloa.

             Before addressing that question, however, we review and

elaborate on our reasons, set forth in the withdrawn panel opinion,

for rejecting the government's argument that appellants waived

their claims of constitutional error.         See Dávila-Reyes, 

.

                                    III.

             The government contends that Reyes-Valdivia and Dávila-

Reyes waived their right to appeal in two distinct ways: by the

express appellate waiver provisions in their plea agreements and

by entry of unconditional guilty pleas to drug trafficking in

violation of the MDLEA.        With respect to Reyes-Valdivia, the

government is wrong in arguing that his appeal is barred by his

plea agreement.     As described above, the district court declined


       Of course, consent by the flag nation changes the calculus,
      12

as acknowledged by one commentator who has advocated for use of
the protective principle in the context of drug-trafficking on the
high seas. See Casavant, supra, at 223 (noting that "consent of
the flag or coastal state" is a "check on the exercise of U.S.
criminal jurisdiction").


                                - 13 -
to follow the parties' recommended term of 57 months and instead

sentenced him to a 70-month term of imprisonment.                         Because Reyes-

Valdivia's         sentence    exceeded          the    recommendation,     the    waiver

provision plainly does not apply.13

               Dávila-Reyes, however, received a 120-month sentence

that aligns with the recommendation in his plea agreement.                              He

argues that, despite the enforceable waiver, we should exercise

our    inherent      authority        to       consider    his   claims    to   avoid   "a

miscarriage of justice."               United States v. Teeter, 

       (1st   Cir.   2001).          He    contends    that   his    appeal   raises

"important questions of law and [of] first impression" -- including

the constitutionality of § 70502(d)(1)(C) of the MDLEA -- and that

preventing him from bringing his appeal would be unjust.

               We agree that the constitutional issue Dávila-Reyes

raises is significant and that the other factors allowing us to

exercise our discretion to disregard the appellate waiver also are

sufficiently present.              See, e.g., United States v. Ortiz-Vega, 

 (1st Cir. 2017).                        Particularly important is the

lack    of    prejudice       to    the    government,       given   Reyes-Valdivia's



       The government contends that Reyes-Valdivia is nonetheless
       13

bound by the waiver provision because he failed to explain in his
opening brief why it is inapplicable. However, it is apparent on
the face of the plea agreement that Reyes-Valdivia was not
sentenced in accordance with the sentencing recommendation
provision, and he was not obligated to make that obvious point in
his opening brief. See United States v. Colón-Rosario, 

 (1st Cir. 2019).


                                           - 14 -
presentation of the same issues as Dávila-Reyes.                  See id. at 27.

Moreover, the potential for                relief should not depend on the

happenstance that the district court added an enhancement to Reyes-

Valdivia's sentence.          Thus, we exercise our discretion and decline

to enforce Dávila-Reyes's appellate waiver.

             Nor do appellants' guilty pleas foreclose their right to

challenge the constitutionality of the MDLEA.                  The Supreme Court

held in Class v. United States that "a guilty plea by itself" does

not    bar   "a    federal     criminal     defendant   from    challenging   the

constitutionality of the statute of conviction on direct appeal."

 (2018).           In their briefing and oral argument,

appellants        present    claims   that    are   permissible    under   Class.

Although they conceded through their guilty pleas that the MDLEA,

by its terms, allows the government to prosecute them under U.S.

law, they argue that Congress exceeded constitutional limits with

the enactment of            the applicable provision.          In other words,

appellants contend that their convictions were within the scope of

the statute but nonetheless unconstitutional.                   Such claims may

proceed notwithstanding an unconditional guilty plea.                 See 

 (holding that a guilty plea does not bar claims that challenge

"the    Government's         power    to     criminalize   [the     defendant's]

(admitted) conduct" because "[t]hey thereby call into question the

Government's power to 'constitutionally prosecute him'" (quoting

United States v. Broce, 

 (1989))).


                                       - 15 -
             The government asserts that Class does not apply here

because appellants "admitted without qualification that their

vessel was one 'subject to the jurisdiction of the United States,'"

without limiting the basis for jurisdiction to § 70502(d)(1)(C)

(whose text is reproduced in footnote 7).14             Appellee's Supp. Br.

at 18-19.     In making that assertion, the government cites to the

appellants' general acknowledgment of guilt at their change-of-

plea    hearing   but   disregards       their   specific   admissions.     The

prosecution -- and, accordingly, appellants' admissions of guilt

--     was   premised    on      their     vessel's    statelessness      under

§ 70502(d)(1)(C).          The     indictment      stated    generally     that

jurisdiction was based on appellants' vessel being one without


        The statutory phrase "a vessel subject to the jurisdiction
       14

of the United States" in the MDLEA concerns legislative
jurisdiction -- in other words, Congress's authority to enact
legislation "regulat[ing] drug trafficking on [] ships" -- rather
than the subject-matter jurisdiction of the federal courts.
United States v. González, 

 (1st Cir. 2002); see
also United States v. Prado, 

 (2d Cir. 2019)
(adopting and elaborating on this interpretation and rejecting the
alternative approach of other circuits). But see United States v.
Miranda, 

 (D.C. Cir. 2015) (agreeing with the
Fifth and Eleventh Circuits that "the question of whether a vessel
is 'subject to the jurisdiction of the United States' is a matter
of subject-matter jurisdiction"). "Unlike Congress's employment
in other statutes of one-factor jurisdictional elements such as
'by a Federal Reserve Bank,' or 'affect[ing] interstate commerce,'
the facts that may cause a vessel to be 'subject to the
jurisdiction of the United States' [under the MDLEA] involve
numerous complex alternatives, which are spelled out at length in
§ 70502 under 'Definitions.'" Prado, 

. Although
appellants assert that their challenge to their prosecution
implicates subject-matter jurisdiction, our precedent, as noted
above, holds otherwise.


                                     - 16 -
nationality, see 

(c)(1)(A),15 but the Department

of State Certification that subsequently was filed specified that

"the Government of the United States determined the vessel was

without      nationality     in     accordance      with    

(d)(1)(C)," Reyes-Valdivia, ECF No. 46-2, at 3 (Mar. 25,

2016)      (Dep't   of   State    Certification)     (emphasis   added).

Appellants' plea agreements also identified § 70502(c)(1)(A) --

i.e., the subsection referring to vessels "without nationality" -

- as the basis for U.S. jurisdiction, see          id., ECF Nos. 68, 72,

at 1-2 (Apr. 4, 2016), and the "Government's Version of the Facts,"

incorporated into those agreements, set forth the facts concerning

the vessel's status in language tracking the requirements of

§ 70502(d)(1)(C): the master's claim of Costa Rican nationality

and the response from the government of Costa Rica "that it could

neither confirm nor refute the registry of the suspect vessel,"

id. at 11.    The same facts were recounted by the government at the

change-of-plea hearing.      See id., ECF No. 117, at 26 (Oct. 3,

2016).16    The government's Motion in Limine and Memorandum of Law


     15As previously noted, § 70502(c)(1) lists "a vessel without
nationality" among the list of vessels that are "subject to the
jurisdiction of the United States." 

(c)(1)(A).
Other types of vessels on the list include "a vessel registered in
a foreign nation if that nation has consented or waived objection
to the enforcement of United States law by the United States," 

§ 70502(c)(1)(C), and "a vessel in the customs waters of the United
States," id. § 70502(c)(1)(D).
     16At the plea hearing, the government was asked to "give a
brief explanation of the theory to be presented to prove each


                                  - 17 -
in Support of Jurisdiction17 likewise asked the district court to

"find, as a matter of law, that [appellants'] vessel was subject

to   the   jurisdiction   of   the   United   States,   as   defined   in

. . . Sections 70502(c)(1)(A) and (d)(1)(C)."      Id., ECF No. 46, at

4 (Mar. 25, 2016).18



Defendant guilty if a trial were to be held."           Id. at 25.     In
relevant part, the prosecutor stated:
                The vessel was tracked by aircraft and
           eventually came to a stop.     The U.S. Coast
           Guard boarding team approached the vessel and
           commenced right of approach questioning.
                The    master    claimed    Costa    Rican
           nationality for the vessel but provided no
           registration[] paperwork, and there was no
           indicia of nationality on the vessel.
                The   Government   of   Costa   Rica   was
           approached. They responded they could neither
           confirm nor refute the registry of [the]
           suspect vessel.
                The vessel was determined to be one
           without nationality.

Id. at 25-26.
     17 In a 1996 amendment to the MDLEA, Congress stated that
jurisdictional issues under the statute "are preliminary questions
of law to be determined solely by the trial judge." 

(a); see also González, 

.      Appellants
moved to change their pleas a week after the government filed the
Motion in Limine, and the district court therefore did not rule on
it. See Reyes-Valdivia, ECF Nos. 59, 63 (Apr. 1, 2016).
     18 The government has continued to rely on § 70502(d)(1)(C)
before us.    In its initial brief, the government quoted the
provision in full and then described appellants' admission
consistently with the provision's terms -- i.e., "that Costa Rica
did not confirm the registry of their vessel (which had no indicia
of nationality) and that their vessel was determined to be one
without nationality."    Appellee's Br. at 36.    In addition, in
asserting that the MDLEA provided sufficient and unambiguous
notice of the MDLEA's applicability to appellants, the government


                                 - 18 -
            Appellants thus pleaded guilty based on the government's

assertion    of   jurisdiction    pursuant   to   § 70502(d)(1)(C),      in

accordance with the facts stated in their plea agreements.               In

other words, they admitted that they "did what the indictment

alleged" and that the government accurately described the facts

giving rise to U.S. jurisdiction under § 70502(d)(1)(C).           Class,

. Hence, their challenge to the constitutionality

of   § 70502(d)(1)(C)   does     not   "contradict   the   terms   of   the

indictment or the written plea agreement," and, as in Class, the

constitutional claim can "be 'resolved without any need to venture

beyond th[e] record.'"      Id. (quoting Broce, 

).

Appellants' constitutional challenge is premised on the facts set

forth by the government and legal principles that, they claim,

invalidate § 70502(d)(1)(C)'s definition of a "vessel without

nationality" as a basis for subjecting them to U.S. jurisdiction.

We need not go outside the existing record to address that question

of law.     Consequently, appellants' guilty pleas do not bar this

direct appeal.    See id. at 805.

            The government also appears to argue, however, that it

is entitled to sidestep appellants' claim that § 70502(d)(1)(C) is



stated: "The absence of an assertion by the Costa Rican government
rendered the Appellants' boat a 'vessel without nationality,' [46
U.S.C.] § 70502(d)(1), and thus a 'vessel subject to the
jurisdiction of the United States,' id. § 70502(c)(1)(A)." Id. at
38.


                                  - 19 -
unconstitutional because, it says, their vessel could have been

deemed without nationality based on other jurisdictional theories

and other facts. In its supplemental brief, the government asserts

that Reyes-Valdivia's failure to produce registration paperwork or

otherwise     substantiate     his   verbal   claim    of    nationality   would

suffice to "render[] the vessel stateless as a matter of domestic

and international law."          Appellee's Supp. Br. at 9 (emphasis

omitted).19    The government further notes that the vessel could be

deemed stateless because it "had no indicia of nationality other

than    the   master's   say-so,     and   even   he   presented    conflicting

information,      having     initially     stated      the    vessel    had   no

nationality."     Id. at 11 (internal quotation marks omitted).               But

these jurisdictional theories are not the basis on which the

government relied to arrest and prosecute appellants, and to obtain

their guilty pleas.        The defendants therefore had no reason or

opportunity to consider those rationales for deeming their vessel

stateless before deciding to forgo their right to contest the MDLEA

charges,20    which   relied    on   the   undisputed       facts   establishing


       This theory also plays a part in the government's defense
       19

of § 70502(d)(1)(C), and we address it in that context in Section
V.C.
        In his supplemental brief, Reyes-Valdivia challenges the
       20

government's assertion that the vessel bore no indicia of
nationality.   He contends that "[p]hotos of the vessel clearly
show the civil ensign of Costa Rica painted, albeit vertically, on
the port and starboard sides of the ship's bow," and he points out
that "the Costa Rica ensign was prominent enough for a Marine
Patrol Aircraft ['MPA'] to recognize it from overhead."


                                     - 20 -
statelessness under § 70502(d)(1)(C).21   It is now simply too late

for the government to proffer alternative bases for jurisdiction.

Cf. United States v. Mitchell-Hunter, 

, 50 n.7 (1st

Cir. 2011) (stating that jurisdiction under the MDLEA may be

established "any time prior to trial" (emphasis added)).

          In sum, neither of the government's waiver-of-appeal

arguments has merit.


Appellants' Supp. Br. at 18 n.4. The assertion of visibility from
the air was based on the statement of Customs Officer Luis Rosado
recounting that the MPA had detected a go-fast vessel "with a Costa
Rican flag painted on the bow." Reyes-Valdivia, ECF No. 46-1, at
1 (Mar. 25, 2016).      The government properly points out that
appellants admitted in their plea agreements to a version of the
facts stating that their vessel bore no indicia of nationality and
argues that appellants "may not pursue any contention on appeal
that 'would contradict' that admission."         Appellee's Supp.
Response Br. at 5 (quoting United States v. Sarmiento-Palacios,

 (1st Cir. 2018)).     However, the government, too,
must abide by the facts on which it relied to obtain appellants'
pleas.
     21 We also note that the government has argued, on the one
hand, that "[t]he MDLEA is . . . clear about how the United States
decides whether a vessel is stateless," citing 

(d), Appellee's Br. at 35, but, on the other hand, has not
identified a statutory provision that matches its newly offered
theories of jurisdiction. As described more fully infra, the two
other circumstances for classifying a vessel as "without
nationality" expressly stated in § 70502(d)(1) -- the denial of a
claim by the named country and the master's refusal to make a claim
upon request -- do not apply here. See 

(d)(1)(A),
(B). Although § 70502(d)(1)'s categories of stateless vessels are
non-exclusive (the provision states that "the term 'vessel without
nationality' includes" the three listed examples (emphasis
added)), the government cannot reasonably expect defendants to
assess their options if it invokes a particular statutory basis
for    jurisdiction    but   reserves    the   right    to    shift
theories -- including to theories beyond the statute's express
language.


                              - 21 -
                                      IV.

           We must consider one last issue before reaching the

merits of appellants' claims.              As our colleague notes in his

concurrence,    the    jurisdictional       provision     relied      on    by    the

government to prosecute appellants, 

(d)(1)(C),

refers to a vessel master's having made a claim of registry, but

Reyes-Valdivia claimed Costa Rican nationality, not registry.                     The

parties    initially    appeared      to    agree   that      § 70502(d)(1)(C)

nonetheless applies to the facts of this case.               In a supplemental

brief submitted in response to questions from the court, however,

appellants argued for the first time that the provision is inapt

where the master of the vessel asserts only a nationality claim.

           We are unpersuaded that this distinction between a claim

of registry and a claim of nationality provides a basis for

vacating    appellants'      convictions.           Although          the        terms

"nationality"    and     "registry,"        in   formal      usage,        are    not

interchangeable,22     the   MDLEA    treats     them   as    such    throughout




     22 In general, the "nationality" of a vessel refers to the
country that has certain "international rights and duties . . . in
connection with a given ship and its users." Herman Meyers, The
Nationality of Ships 129 (1967). The term "registration" refers
to the recording of nationality "on land and under the supervision
of a government body." Id.; see also id. at 129-30 ("The purpose
of a register is to declare the nationality of a vessel engaged in
trade with foreign nations, and to enable her to assert that
nationality wherever found." (quoting The Mohawk, 

 (1865))).


                                     - 22 -
§ 70502.         Section 70502(e), for example, jointly defines a "claim

of nationality or registry" to "include[] only":

                 (1) possession on board the vessel and
                 production   of  documents   evidencing    the
                 vessel's nationality as provided in article 5
                 of the 1958 Convention on the High Seas;[23]
                 (2) flying its nation's ensign or flag; or
                 (3) a verbal claim of nationality or registry
                 by the master or individual in charge of the
                 vessel.

(e).            By allowing the act of flying a national

flag or the possession of documents of nationality to suffice as

a claim to either nationality or registry, the MDLEA effectively

treats       the    distinction    between   nationality    and   registry   as

irrelevant.         Congress's use of the two terms interchangeably, or

at least inconsistently, is even more evident in § 70502(d)(1)(C),

where the rejection of a master's claim of registry is premised on

the named country's failure to confirm nationality.

                 Yet, this variation in terminology does not undermine

what        is   otherwise   Congress's      clear   intention    to   require

verification          when   a      master     identifies    a    vessel     as

"foreign" -- whether by claiming nationality or registry -- and

thereby seeks to avoid the jurisdiction possessed by the United

States (and all nations) over stateless vessels.                  As we shall


        Article 5
       23               states, in part, that "[e]ach State shall issue
to ships to which       it has granted the right to fly its flag documents
to that effect."         United Nations Convention on the High Seas art.
5, Apr. 29, 1958        ("1958 Convention on the High Seas"), 13 U.S.T.
2312.


                                      - 23 -
explain, we think it evident that Congress used the term "claim of

registry" in the first part of § 70502(d)(1)(C) to also encompass

a "claim of nationality" -- a common, albeit imprecise, choice of

language.

            More than fifty years ago, one scholar noted the tendency

to use the term registration to signify the broader concept of

nationality. See Herman Meyers, The Nationality of Ships 28 (1967)

(noting   that   "[t]he   phrase   'registered   in',   and   other   word

combinations in which the term register is used," are sometimes

imprecisely "used as synonymous with nationality"); id. at 127

(noting that, because "in the great majority of cases" nationality

and registration, along with documentation and flying the flag,

"occur in combination," "the differences between the terms have

sometimes been neglected and a pars pro toto [a part taken for the

whole] use of the word registration . . . is by no means rare in

the doctrine or in the sources of international law").         Indeed, a

claim of registry is also a claim of nationality.        See supra note

22.   Thus, the variable word choice in § 70502(d)(1)(C) does not

have the import that it might have in other contexts.                  See

generally DePierre v. United States, 

 (2011) (noting

the usual assumption that a legislature intends different meanings

when it uses different words, but also recognizing that "Congress

sometimes uses slightly different language to convey the same

message").


                                   - 24 -
            Importantly, notwithstanding the prior reference to a

claim of registry in § 70502(d)(1)(C), Congress's ultimate demand

in that same provision is for confirmation of nationality.                            We can

detect    no    reason      why       Congress        would          require    affirmative

confirmation when a vessel's master makes a claim of registry,

while    allowing    a    claim      of    nationality          to    stand    on   its    own.

Excluding claims of nationality from the provision's scope would

allow    drug   traffickers          to    evade     the    verification         requirement

simply by asserting a claim of nationality.                          Appellants attribute

that glaring loophole to Congress's deference to foreign nations

and its intention to stay within the bounds of international law.

They note that a claim of nationality "presents a more complicated

scenario since not all national ships are registered," making it

more difficult for the claimed nation "to confirm or refute the

nationality claim."        Appellants' Supp. Br. at 8-9.                       Appellants do

not explain, however, why that concern would prompt Congress, in

effect,    to   nullify     the      verification          provision      by     encouraging

vessel masters to claim foreign nationality rather than registry.

Inescapably,      then,        the        reference        in    the     first      part     of

§ 70502(d)(1)(C)         solely       to    "a     claim        of    registry"     must    be

attributable to the not infrequent practice of treating a "claim

of   registry"      and    a    "claim        of     nationality"         as    essentially

synonymous, even though the former term is technically narrower

than the latter.


                                            - 25 -
              Our   view    that   § 70502(d)(1)(C)         is   not      reasonably

construed as limited to claims of registry is reinforced when the

provision is considered in the context of the MDLEA as a whole and

in light of its legislative history. See, e.g., Abramski v. United

States, 

, 179 n.6 (2014) ("[A] court should not

interpret each word in a statute with blinders on, refusing to

look    at    the   word's    function    within      the    broader      statutory

context."); United Sav. Ass'n of Tex. v. Timbers of Inwood Forest

Assocs., Ltd., 

 (1988) ("Statutory construction

. . . is a holistic endeavor.          A provision that may seem ambiguous

in isolation is often clarified by the remainder of the statutory

scheme -- because the same terminology is used elsewhere in a

context that makes its meaning clear, or because only one of the

permissible     meanings     produces    a     substantive       effect    that   is

compatible with the rest of the law." (citations omitted)).                       The

MDLEA   reflects      Congress's   intention     to   enable      the     aggressive

prosecution of maritime drug trafficking.              See 

("Congress finds and declares that . . . trafficking in controlled

substances aboard vessels is a serious international problem, is

universally condemned, and presents a specific threat to the

security and societal well-being of the United States . . . .").

Indeed, § 70502(d)(1)(C) was among several provisions added to the

MDLEA    in    1996    to    "expand     the    Government's       prosecutorial

effectiveness in drug smuggling cases."            H.R. Rep. No. 104-854, at


                                    - 26 -
142 (1996) (Conf. Rep.), reprinted in 1996 U.S.C.C.A.N. 4292, 4337.

Given this statutory backdrop, the majority observed in United

States v. Matos-Luchi that "Congress did not expect courts to

render a cramped reading of the statute."     

, 7 (1st Cir.

2010).

           In addition, other portions of the MDLEA's legislative

history indicate that Congress's specific reference to a claim of

registry in subsections (A) and (C) of § 70502(d)(1) -- both

involving the claimed nation's response (or lack thereof)24 -- may

reflect the fact that registry claims appear to have been the

common way in which drug-trafficking defendants asserted their

foreign   nationality.    There   are   multiple   references   to   the

difficulty   faced   by   prosecutors    in   producing   "judicially

admissible documentary evidence" of the foreign nation's "consent

[to board] or denial of a claim of registry."      S. Rep. No. 99-530,

at 15 (1986) (emphasis added); see also, e.g., USCG Authorizations

and Load Lines: Hearing on H.R. 1362 Before the S. Subcomm. on

Merchant Marine of the Comm. on Commerce, Sci. & Transp., 99th

Cong. 39-40 (1986) (Responses of Adm. James Gracey to questions




     24 Like § 70502(d)(1)(C), see supra note 7, subsection
(d)(1)(A) specifically references a claim of registry, stating
that a "vessel without nationality" includes any vessel "aboard
which the master or individual in charge makes a claim of registry
that is denied by the nation whose registry is claimed."


                               - 27 -
from Sen. Hollings).25   But whatever the exact explanation for the

chosen language, given the legislative background, together with


     25This hearing, in May 1986, preceded the adoption that year
of the MDLEA. Asked to "describe the kinds of problems the Coast
Guard and federal prosecutors have encountered" in responding to
jurisdictional objections from accused drug traffickers at trial,
Admiral Gracey responded, in part, as follows:
          The princip[al] problems that have arisen
          involve the difficulty of proving vessel
          status. For [e]xample, if upon inquiry by the
          Coast Guard, a vessel makes a claim of
          registry, the U.S. must confirm that registry
          with the claimed flag state. If the flag state
          denies registry, the vessel is stateless,
          i.e., a "vessel subject to the jurisdiction of
          the United States" . . . . At this point, the
          U.S. may under international law take law
          enforcement action against that vessel.
          However, to prove the element of the offense
          in court, the U.S. must obtain a formal
          certification from the claimed flag state
          attesting that the vessel is not registered in
          that state.      On the other hand, i[f] the
          claimed state verifies registry, the U.S.
          obtains that state's consent to take law
          enforcement action. . . . However, to prove
          the element of the offense in court, the
          United    States    must   obtain   a   formal
          certification from the flag state verifying
          registry and confirming its consent for the
          U.S. to take law enforcement action.       The
          difficulties in obtaining these documents from
          foreign governments in a timely manner, and in
          a form acceptable to our courts under the
          Federal    Rules   of   Evidence,  have   been
          considerable.

USCG Authorizations and Load Lines: Hearing on H.R. 1362 Before
the S. Subcomm. on Merchant Marine of the Comm. on Commerce, Sci.
& Transp., 99th Cong. 39-40.
     A focus on registry as the common indicator of nationality
also appears in the legislative history of the MDLEA's predecessor,
the Marijuana on the High Seas Act, 

 Stat.


                               - 28 -
Congress's blending of the concepts of nationality and registry

elsewhere in the MDLEA, a reading of § 70502(d)(1)(C) that excludes

claims of nationality would "produce[] a substantive effect that

is [in]compatible with the rest of the law."        United Sav. Ass'n of

Tex., 

.

            We note, in addition, that this court has treated claims

of registry and nationality synonymously in multiple cases.              For

example, in Matos-Luchi, the majority cited § 70502(d)(1)(A) and

(C) -- both of which refer only to a claim of registry -- as

applicable to a "claim of nationality [that] is made but rejected

[(d)(1)(A)] or not backed up by the nation invoked [(d)(1)(C)]."

627 F.3d at 6; see also United States v. Cuevas-Esquivel, 

 (1st Cir. 1990) (noting the absence of a claim of

nationality but citing to a provision in an earlier codification

of   the   MDLEA   that   referenced   only   registry   (46   U.S.C.   App.

§ 1903(c)(2)(A))); United States v. Maynard, 

(1st Cir. 1989) ("Since a 'claim of nationality' was made, the


1159 (1980). See, e.g., Stopping "Mother Ships" -- A Loophole in
Drug Enforcement: Hearing Before the S. Subcomm. to Investigate
Juvenile Delinquency of the Comm. on the Judiciary, 95th Cong., at
52 (1978) (Statement of Morris Busby, Acting Deputy Assistant Sec.
of State for Oceans and Fisheries Affairs) (noting the "well-
established principle under international law . . . that a country
may exercise jurisdiction on the high seas over a vessel without
nationality, one that is not registered in any foreign state");
id. at 53 (explaining that, when the master or crew make "a claim
of nationality," the Coast Guard's protocol involves contacting
the claimed flag state to "request[] that the government verify
the registry of the vessel").


                                  - 29 -
[vessel] can be classified as a stateless vessel only if the 'claim

is denied by the flag nation whose registry is claimed.'" (quoting

§ 1903(c)(2)(A))).

           Other     courts   have     likewise        used    the    terms

interchangeably.     See United States v. Alarcon Sanchez, 

, 162-63 (2d Cir. 2020) (stating that "[a] claim of registry

may be made" by "'a verbal claim of nationality or registry,'"

quoting 

(e) and relying on § 70502(d)(1)(C) in

discussing the master's assertion of nationality); United States

v. Prado, 

 (2d Cir. 2019) ("[A] verbal assertion

of nationality by the master constitutes a claim, which is then

tested by a U.S. officer's inquiry of the nation's registry

authority."); United States v. Hills, 

, 253 (11th

Cir. 2018) (per curiam) (finding that the defendant's vessel was

without nationality based on § 70502(d)(1)(C) where the defendant

"told [the Coast Guard] that he was the master of the vessel and

identified the vessel as Costa Rican"); United States v. Rosero,

 (3d Cir. 1994) (referring to "a false claim of

nationality or registry" even though the provision at issue, 46

U.S.C.   App.   § 1903(c)(2)(A),     referred   only    to    "a   claim   of

registry"); id. at 174 ("[T]he prosecution can establish that a

vessel is stateless by showing that the master or person in charge




                                - 30 -
made a claim of nationality or registry that was denied by the

flag nation whose registry was claimed.").26

          We therefore see no basis for departing from our prior

understanding of § 70502(d)(1)(C)'s scope.27   Congress's reference

solely to claims of registry in the first part of § 70502(d)(1)(C)

is not reasonably construed to exclude from that subsection's

verification requirement claims of nationality that are phrased

without reference to registration.28



     26The government in this case also blended the two concepts.
Despite the claim solely of nationality, the United States asked
Costa Rica to confirm "registry or nationality." Costa Rica then
"replied that it could not confirm [the] vessel's registry." See
Reyes-Valdivia, ECF No. 46-2, at 1 (Mar. 25, 2016) (Dep't of State
Certification).
     27 In so concluding, we note that, contrary to appellants'
assertion, the statutory imprecision here is not an instance of
ambiguity requiring application of the rule of lenity. The rule
of lenity, which "requires that ambiguity in a criminal statute be
resolved in favor of the accused," United States v. Jimenez, 

 (1st Cir. 2007), "does not apply if the ambiguous
reading relied on is an implausible reading of the congressional
purpose," Caron v. United States, 

 (1998). As we
have described, Congress clearly intended to subject a claim of
nationality that is not premised on registry to the same
verification requirement as a claim of registry. Accordingly, the
rule of lenity does not come into play.       See Moskal v. United
States, 

 (1990) ("[W]e have always reserved lenity
for those situations in which a reasonable doubt persists about a
statute's intended scope even after resort to the language and
structure, legislative history, and motivating policies of the
statute." (internal quotation marks omitted)).
     28Although we do not rely on waiver in rejecting appellants'
belated argument that § 70502(d)(1)(C) does not apply to the facts
of this case, we note that a request for supplemental briefing
does not revive a claim that a party has failed to preserve. See
United States v. Galíndez, 

, 69 n.10 (1st Cir. 2021).


                              - 31 -
                                            V.

            Having addressed these threshold issues, we turn to

appellants'           constitutional         challenge         to    

(d)(1)(C).            As described above, we have construed that

provision to allow U.S. authorities to deem a vessel "without

nationality" -- i.e., stateless -- when a claim of either registry

or nationality asserted by the vessel's occupants is neither

confirmed nor denied by the claimed country.                    See, e.g., Matos-

Luchi, 627 F.3d at 6.              Under Aybar-Ulloa, a determination of

statelessness         has     a   significant     consequence:       it     permits

prosecution under U.S. law of any foreign national aboard the

vessel.         See    

.      Appellants     contend     that

§ 70502(d)(1)(C) exceeds Congress's authority under the "Define

and Punish Clause" of Article I, which gives Congress the power

"[t]o define and punish Piracies and Felonies committed on the

high Seas, and Offences against the Law of Nations."                    U.S. Const.

art. I, § 8, cl. 10.

            It is undisputed that the "vessel without nationality"

provisions of the MDLEA were enacted solely pursuant to Congress's

authority to "define and punish . . . Felonies committed on the

high    Seas"   ("the       Felonies   Clause").29       See   United     States   v.


       Although it may be more accurate to refer to the "Felonies
       29

Clause" as the "Felonies Sub-Clause," given that it is contained
within the Define and Punish Clause, we use the "Felonies Clause"
designation for simplicity.


                                        - 32 -
Cruickshank, 

 (11th Cir. 2016) (stating that

the MDLEA "was enacted under Congress's authority provided by the

Felonies Clause"). Appellants argue that the definition of "vessel

without     nationality"         in    § 70502(d)(1)(C)           conflicts    with

international law and thus authorizes the arrest and prosecution

of foreign nationals aboard vessels on the high seas that the

Constitution does not permit.           This assertion of U.S. jurisdiction

is incompatible with the Constitution, appellants contend, because

Congress's authority under the Felonies Clause is constrained by

international law.          Put another way, appellants ask us to conclude

that, under longstanding principles of international law, their

vessel was not properly deemed stateless, and because Congress's

authority       in   this   instance   is    limited   by    international     law,

appellants' arrests and prosecution were unconstitutional.

            We review appellants' challenge to the constitutionality

of a federal statute de novo.               See United States v. Booker, 

 (1st Cir. 2011).           We begin by describing existing law

on the MDLEA, and then consider the origins and meaning of the

Define    and    Punish     Clause    generally,   and      the   Felonies    Clause

specifically, before assessing whether § 70502(d)(1)(C) of the

MDLEA violates the jurisdictional limits imposed by the Felonies

Clause.




                                       - 33 -
A.   Statutory Background and Overview of Case Law on the MDLEA

            The MDLEA makes it unlawful for persons "on board a

covered vessel . . . [to] knowingly or intentionally . . .

manufacture or distribute, or possess with intent to manufacture

or distribute, a controlled substance."     

(a)(1).

The MDLEA's prohibitions apply "even though the act is committed

outside the territorial jurisdiction of the United States," 

§ 70503(b), and "a covered vessel" includes, inter alia, any

"vessel subject to the jurisdiction of the United States," id.

§ 70503(e)(1).30   As relevant here, the Act defines "vessel subject

to the jurisdiction of the United States" to include any "vessel

without nationality." Id. § 70502(c)(1)(A).

            A vessel is expressly considered "without nationality"

-- or stateless -- under the MDLEA in three circumstances.     First,

that label applies when "the master or individual in charge fails,"

when asked by U.S. law enforcement, "to make a claim of nationality

or registry for th[e] vessel."     Id. § 70502(d)(1)(B).     As noted

above, a claim of nationality or registry can be made by presenting

documents    demonstrating   nationality,   "flying   [the   claimed]

nation's ensign or flag," or verbally asserting nationality or


     30 Another subsection of the statute defines "covered vessel"
to include "any other vessel if the individual [allegedly engaged
in drug activity] is a citizen of the United States or a resident
alien of the United States." 

(e)(2). At issue
in this case is U.S. jurisdiction over foreigners, and we therefore
do not consider the MDLEA's application to U.S. nationals.


                               - 34 -
registry.   

 § 70502(e)(1)-(3).   Second, a vessel is considered

stateless if its master does make a claim of nationality or

registry, but the nation identified denies the claim when contacted

by U.S. officials.     Id. § 70502(d)(1)(A).    Third, a vessel is

considered stateless when the country whose nationality is claimed

"does not affirmatively and unequivocally assert that the vessel

is of its nationality." Id. § 70502(d)(1)(C). This last situation

-- the foundation for appellants' arrest and prosecution -- is the

focus of the constitutional challenge now before us.31

            Despite the frequency with which MDLEA cases arise in

this circuit, waiver and other threshold procedural issues have

prevented us from fully addressing the merits of a challenge under

Article I to any portion of the MDLEA.         See United States v.

Sarmiento-Palacios, 

 (1st Cir. 2018) (finding a

challenge to the constitutionality of the MDLEA waived where the

defendant failed to develop the argument and conceded that "the

MDLEA is a valid exercise of Congress's Article I powers"); United

States v. Díaz-Doncel, 

 (1st Cir. 2016) (holding,

before Class, that the defendant had waived the right to challenge

the constitutionality of    the MDLEA on appeal     by entering an



     31A vessel also may be treated as stateless under the MDLEA
if it displays more than one country's flag "and us[es] them
according to convenience."   1958 Convention on the High Seas,
supra, art. 6 (incorporated into the MDLEA at 

(c)(1)(B)).


                              - 35 -
unconditional guilty plea); United States v. Nueci-Pena, 

 (1st Cir. 2013) (addressing defendant's Article I

challenge to the MDLEA under plain error review because the

argument was not raised in the district court and concluding that

there was no plain error in light of the lack of First Circuit and

Supreme Court precedent addressing the constitutionality of the

MDLEA); United States v. Cardales-Luna, 

 (1st

Cir. 2011) (holding that, because the constitutionality of the

MDLEA did not implicate the court's subject matter jurisdiction,

it was not appropriate for the court to raise the issue sua

sponte).

              In Aybar-Ulloa, the en banc court was presented with a

preserved constitutional challenge.        The defendant argued that

Article I did not give Congress the authority to assert U.S.

jurisdiction over stateless vessels that have no nexus to the

United States, basing his argument on the asserted existence of a

nexus requirement in international law.             See 

(Barron, J., concurring) (elaborating Aybar-Ulloa's constitutional

claim).    The en banc court did not address Congress's authority

under   the    Constitution,   however,   because    it   concluded   that

international law permits the United States to prosecute foreign

nationals engaged in drug trafficking on any stateless vessel, at

least when U.S. authorities have boarded and seized the vessel

pursuant to the right of boarding recognized under international


                                 - 36 -
law.        

.32   The court expressly did not "reach the

question of whether the application of the MDLEA to Aybar[-Ulloa]

would be constitutional were international law otherwise."          

.     Aybar-Ulloa does not govern this case.     Unlike the defendant

there -- who admitted that his vessel was stateless -- Reyes-

Valdivia and Dávila-Reyes insist that their vessel was not properly

deemed "without nationality."          They assert that the method of

determining       statelessness   in   § 70502(d)(1)(C)   expands    U.S.

jurisdiction beyond the bounds permitted by the Constitution.

               We have passed upon some related questions, such as

whether another of the "without nationality" provisions of the

MDLEA is consistent with international law, see Matos-Luchi, 627

F.3d at 6-7 (noting that 

(d)(1)(B) is consistent


        The concurring judge in Aybar-Ulloa declined to join the
       32

majority's approach, finding "no clear support in either case law
or commentary for the comparatively modest proposition that
persons on stateless vessels that a foreign country's officials
have seized and boarded pursuant to their recognized right to visit
it are subject to that country's territorial jurisdiction under
international law."     

 (emphasis added).       More
particularly,    the   Aybar-Ulloa   concurrence   observed    that
international law experts have "long noted the disagreement that
exists over" whether "the prevailing view of the law of nations is
that the interdicting country acquires the same territorial
jurisdiction over the vessel's occupants as it acquires over the
vessel itself." 

. Given this lack of support for the
majority's approach, and related concerns, see 

, the
concurring opinion instead rejected Aybar-Ulloa's challenge based
on "the more than two-century-old precedent" addressing "the
United States' power to prosecute defendants of a range of
citizenships and circumstances" "for their felonious conduct on
stateless vessels in international waters." 

 (relying
on United States v. Holmes, 

 (1820)).


                                  - 37 -
with international law allowing a vessel to be deemed stateless if

the master refuses to claim a nationality),33 and whether the

MDLEA's flag-nation consent provisions provide due process, see

Cardales, 

 (holding that "due process is satisfied

when    the   foreign   nation    in   which   the   vessel    is   registered

authorizes the application of United States law to the persons on

board the vessel").      Along with Aybar-Ulloa, these cases provide

a useful backdrop to our discussion of the constitutionality of

§ 70502(d)(1)(C), but they do not answer the question now before

us.

              Although several of our sister circuits have addressed

whether the MDLEA is, in general, a constitutional exercise of

Congress's authority under the Felonies Clause, it appears that no

circuit       has    considered        the     specific       authority    for

§ 70502(d)(1)(C)'s definition of a "vessel without nationality."

Instead, courts have assumed that the MDLEA applies only to vessels

that would be subject to U.S. jurisdiction under international



       In Matos-Luchi, the panel majority made the broad statement
       33

that "the MDLEA is consistent with international law." 627 F.3d
at 6. Read in context, however, that statement refers only to the
jurisdictional provision at issue there -- § 70502(d)(1)(B). The
discussion that follows focuses on deeming a vessel stateless when
there is an attempt "to avoid national identification," and
concludes by asserting that "the instances specified by Congress
-- pertinently, the refusal 'aboard' the vessel to claim
nationality, 

(d)(1)(B) -- are not departures from
international law but merely part of a pattern consistent with
it." 

 (emphasis added).


                                   - 38 -
law, i.e., U.S. vessels and those meeting the international law

definition      of    statelessness.          See,    e.g.,    United     States   v.

Ballestas, 

 (D.C. Cir. 2015) (holding that

Congress had authority under the Felonies Clause to punish a

defendant for conduct committed by his co-conspirators aboard a

stateless vessel on the high seas); United States v. Campbell, 

 (11th Cir. 2014) (stating that "we have long upheld

the authority of Congress to 'extend[] the criminal jurisdiction

of this country to any stateless vessel in international waters

engaged in the distribution of controlled substances'" (quoting

United States v. Marino-Garcia, 

 (11th Cir.

1982)) (alteration in original)); United States v. Estupinan, 

      (11th   Cir.     2006)   (holding     that    the   MDLEA's

punishment of drug trafficking "on board a vessel subject to the

jurisdiction         of   the     United    States"     is     within     Congress's

constitutional authority); United States v. Moreno-Morillo, 

 (9th Cir. 2003) (citing United States v. Davis, 

 (9th Cir. 1990), for the proposition that "this court

clearly has held that the MDLEA is constitutional" in a case where

the statelessness of the vessel was uncontested).                       We have thus

found    no     precedent       squarely     addressing       the   argument     that

appellants make here: that the definition of a "vessel without

nationality" in § 70502(d)(1)(C) is broader than the definition of




                                         - 39 -
a    stateless   vessel   under   international    law    and    is    therefore

unconstitutional.34

            Thus, although we draw on prior cases addressing the

constitutionality     of    the    MDLEA    and   its    relationship       with

international law, the issue before us appears to be one of first

impression for the federal courts.

B.     Constitutional Limits on Congress's Authority to Define and
       Punish Felonies

            As    described       above,     appellants         contend     that

§ 70502(d)(1)(C) of the MDLEA defines "vessel without nationality"

to encompass vessels -- including their own -- that are not in

fact without nationality under international law.                     A conflict

exists, they explain, because the provision treats a vessel as



        Although the same MDLEA provision was at issue in United
       34

States v. Bravo, the defendants argued only that their prosecution
was flawed because the government failed to satisfy a nexus
requirement -- i.e., "that the marijuana transported in the vessel
would affect the United States." 

, 7 (1st Cir. 2007).
We rejected the challenge, stating that "[w]e do not read the MDLEA
to require a jurisdictional nexus."      Id.    Hence, we were not
confronted with the argument asserted here -- that Congress acted
beyond its constitutional authority in adopting § 70502(d)(1)(C).
We note that the author of Bravo subsequently rejected the position
taken in that case. See United States v. Trinidad, 

 (1st Cir. 2016) (Torruella, J., dissenting) ("I can no longer
support the approach taken by this and our sister circuits in
embracing the sweeping powers asserted by Congress and the
Executive under the [MDLEA.]").           Trinidad also involved
§ 70502(d)(1)(C), but the defendant there did not challenge the
government's   determination    that  his    vessel   was  "without
nationality" under that provision or argue that "his plea agreement
must be vacated because Congress exceeded its constitutional
authority under Article I in enacting the MDLEA." Id. at 113 n.1.


                                   - 40 -
stateless despite a claim of nationality being made through a

method long acceptable under international law -- specifically, in

their case, the master's verbal claim -- if the named country does

not "affirmatively and unequivocally assert that the vessel is of

its nationality."       

(d)(1)(C).            In other words,

appellants maintain that § 70502(d)(1)(C) rejects a claim of

nationality in circumstances where international law accepts the

claim. According to appellants, because of this disconnect between

the MDLEA and international law, U.S. authorities who rely on the

definition   of    a    "vessel      without     nationality"    contained   in

§ 70502(d)(1)(C) will impermissibly arrest and prosecute foreign

nationals on a foreign vessel -- which is what they say occurred

in this case.

          Appellants' assertion of improper arrest and prosecution

depends on two propositions involving international law: first,

that Congress's authority to "define and punish . . . Felonies

committed on the high Seas," U.S. Const. art. I, § 8, cl. 10, is

limited by principles of international law and, second, that

§ 70502(d)(1)(C)       allows    the    United    States   to    deem   vessels

stateless even when they would not be deemed stateless under

international     law.          If     both     propositions    are     correct,

§ 70502(d)(1)(C) would unconstitutionally permit U.S. authorities

to assert jurisdiction over vessels that would not be stateless

under international law. In that scenario, the United States would


                                       - 41 -
be imposing its law on foreign individuals on foreign vessels --

an extension of jurisdiction that ordinarily is impermissible.

See, e.g., Aybar-Ulloa, 

 (noting that "the flag-state

system guarantees freedom of navigation in international waters,

as states generally may not interfere with the passage on the high

seas of ships lawfully flying the flag of another state" (citing

Richard A. Barnes, "Flag States," in The Oxford Handbook on the

Law of the Sea 313 (Rothwell et al. eds. 2015))); 

 (noting

"the    presumption      of   exclusive    flag-state      jurisdiction"     over

vessels with identified nationality).

             Hence, resolving this case requires us first to examine

the intersection between the Felonies Clause and international

law.     To be clear, the claim here is not that international law

itself      constrains    Congress's      authority   to    enact   statutes.35

Rather,     appellants    contend   that     the   Felonies    Clause   of    the

Constitution, by original design, requires Congress to adhere to

the jurisdictional limits of international law with respect to




        The MDLEA states that a person charged under the statute
       35

"does not have standing to raise a claim of failure to comply with
international law as a basis for a defense." 

.
The provision further states that "only . . . a foreign nation"
may raise such a claim and that "[a] failure to comply with
international law does not divest a court of jurisdiction and is
not a defense to a proceeding under this chapter." 

 This bar
does not apply here precisely because defendants are not arguing
that international law itself constrains Congress's authority.


                                    - 42 -
determining statelessness.36      We thus begin our discussion by

examining how the Framers would have understood the authority given

to Congress by the Felonies Clause.

           1.   The Constitution and International Law

           The delegates who gathered to draft the Constitution had

a primary goal of improving the new nation's ability to meet its

obligations to other countries under international law.      See Ryan

Goodman & Derek P. Jinks, Filartiga's Firm Footing: International

Human Rights and Federal Common Law, 

, 464

(1997) ("[T]he Framers held the Constitutional Convention in large

part due to the perceived inability of the Confederation to uphold

American   obligations   under   international   law.").37   When   the

Governor of Virginia, Edmund Randolph, introduced the "Virginia

Plan" that was to become the basis for the Constitution,38 he


     36 Of course, where possible, we construe statutes to be
consistent with international law.    See Murray v. The Schooner
Charming Betsy, 

 (1804); Garcia v.
Sessions, 

 (1st Cir. 2017).
     37 In Filartiga v. Pena-Irala, 

 (2d Cir. 1980),
the Second Circuit held that plaintiffs could bring actions under
the Alien Tort Statute ("ATS") "based on modern human-rights laws
absent an express cause of action created by an additional
statute." Jesner v. Arab Bank, PLC, 

 (2018).
The plaintiffs in Filartiga were the family members of a young man
who had been tortured and murdered by Paraguayan police officers,
one of whom was living in New York. The suit was filed in the
United States District Court for the Eastern District of New York,
and the appeals court found jurisdiction existed under the ATS.
     38 The Virginia Plan was a set of fifteen "republican
Principles" introduced by Randolph for discussion at the
Constitutional Convention. 1 Records of the Federal Convention of


                                 - 43 -
criticized the Articles of Confederation because they did not allow

the federal government to punish states that "act[] against a

foreign power contrary to the laws of nations or violate[] a

treaty" or to compel states to punish their citizens who violate

the law of nations by, for example, "invad[ing]" the rights of an

ambassador.       1 Records of the Federal Convention of 1787 24-25

(Max   Farrand     ed.,    1911)    (hereinafter      "Farrand's    Records").

Likewise,    James   Madison    wrote    to   James   Monroe   in   1784   that

"[n]othing seems to be more difficult under [the Articles of

Confederation] than to impress on the attention of our [state]

Legislatures a due sense of those duties which spring from our

relations to foreign nations."          Letter from James Madison to James

Monroe (Nov. 27, 1784), in 2 The Writings of James Madison 93

(Gaillard Hunt ed., 1901).

            These statements reflect the           Framers' concern that,

without     the    power   to      "enforce   national    treaties    against

recalcitrant states, compel their compliance with the law of



1787 27-28 (Max Farrand ed., 1911). It described in general terms
the governmental structure that was later adopted in significant
part by the Constitution: a bicameral legislature, a national
executive (albeit one elected by the legislature), and a judiciary
with, among other powers, the authority to "determine Piracies,
Captures, [and] Disputes between Foreigners and Citizens."     

Before introducing this plan, Randolph listed five ways in which
the Articles of Confederation did not fulfill "the objects for
which it was framed." Id. at 24. The first of these, as explained
above, was its failure to ensure compliance with international
law. Id. at 24-25.


                                     - 44 -
nations,   punish    offenses     against     that    law,     regulate    foreign

commerce, and so on, the new republic would be unable to obtain

commercial      advantages    and,   given    its     military    weakness        and

perilous   geographic    situation,       would     face   external     threats."

David M. Golove & Daniel J. Hulsebosch, A Civilized Nation: The

Early American Constitution, the Law of Nations, and the Pursuit

of International Recognition, 

, 980 (2010);

see also 

 (explaining that "[d]iplomatic frustrations

resulting from state violations of the Treaty of Peace [with

England], in particular, helped create the atmosphere of crisis

that    motivated    profederal      forces    to     organize    and     write    a

constitution").

           In drafting a new constitution, the Framers thus aimed

"to provide a national monopoly of authority in order to assure

respect for international obligations."               Stewart Jay, The Status

of the Law of Nations in Early American Law, 

,

829 (1989).     The Framers were "commit[ted] to protecting sovereign

interests through rigorous enforcement of the law of nations."

Douglas J. Sylvester, International Law as Sword or Shield? Early

American Foreign Policy and the Law of Nations, 

, 9 (1999); see also Jesner v. Arab Bank, PLC, 

 (2018) (Gorsuch, J., concurring) ("[W]hen the

framers gathered to write the Constitution they included among

their   chief    priorities    endowing     the     national    government    with


                                     - 45 -
sufficient power to ensure the country's compliance with the law

of nations."); Golove & Hulsebosch, supra, at 988 (stating that

the Framers "carefully designed the new Constitution to ensure

that the new nation would uphold its duties under the law of

nations"); Louis Henkin, Foreign Affairs and the United States

Constitution 234 (2d ed. 1996) ("The Framers assumed that the new

federal government would carry out the obligations of the United

States under international law."); Anthony J. Bellia Jr. & Bradford

R. Clark, The Law of Nations as Constitutional Law, 

, 751 (2012) ("Of all the rights that can belong to a nation,

sovereignty is, doubtless, the most precious, and that which others

ought the most scrupulously to respect, they would not do it an

injury." (quoting 1 Emmerich de Vattel, The Law of Nations, bk.

II, § 54, at 138 (London, J. Newberry et al., 1759), "the most

well-known work on the law of nations in England and America at

the time of the Founding," id. at 749)); Beth Stephens, The Law of

Our Land: Customary International Law as Federal Law after Erie,

, 397 (1997) (stating that "the intent of

the framers, incorporated into the Constitution, was to ensure

respect for international law by assigning responsibility for

enforcement of that law to the three branches of the federal

government").   Laws governing interactions on the high seas were

of particular concern: "The framers of the Constitution were

familiar with [the law of the sea] and proceeded with it in mind.


                              - 46 -
Their purpose was not to strike down or abrogate the system, but

to place the entire subject . . . under national control, because

of its intimate relation to navigation and to interstate and

foreign commerce."    Panama R. Co. v. Johnson, 

(1924).

          The Framers' commitment to international law principles

was both pragmatic and ideological.         See Jay, supra, at 822

(explaining that, "[i]n the eighteenth century a consensus existed

that the law of nations rested in large measure on natural law,"

and thus the Framers viewed following the law of nations as a moral

imperative);   Beth   Stephens,    Federalism   and   Foreign   Affairs:

Congress's Power to "Define and Punish . . . Offenses Against the

Law of Nations", 

, 465 (2000) (describing

the Framers' belief that "[e]nforcement of international law norms

was . . . a moral obligation").     Indeed, the Framers believed that

to be a "nation," the United States must honor the law of nations.39


     39 At the time of the founding, the phrase "law of nations"
was generally used to refer to customary international law (i.e.,
law established by universal practice rather than by agreement in
a treaty). See United States v. Bellaizac-Hurtado, 

 (11th Cir. 2012) (stating that "[w]e and our sister circuits
agree that the eighteenth-century phrase, the 'law of nations,' in
contemporary terms, means customary international law," and
collecting cases). However, it was also used as a broader term
for international law, including treaties. See Sarah H. Cleveland
& William S. Dodge, Defining and Punishing Offenses under Treaties,

, 2206-07 (2015) (arguing that "Offences against
the Law of Nations" includes treaty violations). In this case,
where no treaty is at issue, we need not consider the precise
meaning of the term "law of nations" as used by the Framers, and


                                  - 47 -
See Chief Justice John Jay, Charge to the Grand Jury of the

District of New York (Apr. 4, 1790), reprinted in N.H. Gazette

(Portsmouth 1790) (stating, in a charge to a grand jury, that "[w]e

had become a nation -- as such, we were responsible to others for

the observance of the Laws of Nations").       Hence, as they embarked

on drafting a constitution, the Framers saw a federal system

capable of upholding international law as an imperative for the

United States to achieve equal status in the community of nations.

See Aybar-Ulloa, 

 (Barron, J., concurring) ("The

founding generation was attentive to the strictures of the law of

nations.").

           With this backdrop, we think it apparent that the Framers

viewed international law as a restraint on Congress's enumerated

powers   bearing   on   foreign   relations.   As   John   Quincy   Adams

explained, "[t]he legislative powers of Congress are . . . limited

to specific grants contained in the Constitution itself, all

restricted on one side by the power of internal legislation within

the separate States, and on the other, by the laws of nations."

John Quincy Adams, The Jubilee of the Constitution 71 (1839)

(emphasis added).




we henceforth use the modern term "international law" to refer to
the body of law that includes both customary international law and
treaties.


                                  - 48 -
            There is a particular justification for interpreting the

Define and Punish Clause in relation to the Framers' understanding

of international law principles.        The Define and Punish Clause, of

which the Felonies Clause is a part, refers to "Offences against

the Law of Nations," "Piracies," and "Felonies" -- all concepts

taken directly from international law.            See Banco Nacional de Cuba

v.   Sabbatino,   

,   451    &   n.13   (1964)   (White,     J.,

dissenting) (noting that the language of the Define and Punish

Clause shows the Framers' belief that "the law of nations is a

part of the law of the land"); Golove & Hulsebosch, supra, at 1009

(stating that "[t]his deliberate borrowing suggest[s] that the

established principles of the law of nations might define the scope

of the [congressional] powers themselves").              These phrases, found

in the leading international law treatises of the day,                       were

familiar shorthand for complex international law concepts.                   Their

use in the Constitution is thus strong evidence that the Framers

intended    the   Define    and   Punish      Clause     to   align   with    the

international law understanding of those terms.               See 3 Emmerich de

Vattel, The Law of Nations 295 (1758) (Charles G. Fenwick trans.,

1916) (referencing "offenses against the Law of Nations"); 4

William    Blackstone,     Commentaries      *67-71    (discussing    "offences

against the law of nations," and defining "piracy" as one such

offense); 3 Sir Edward Coke, The Institutes of the Laws of England




                                   - 49 -
111 (1644) (describing "Piracies, and felonies . . . done on the

sea").

             International law thus informs our inquiry into the

meaning of the Define and Punish Clause and, specifically, the

Felonies portion of the Clause.

             2.    The Meaning of the Felonies Clause

             As noted above, the Define and Punish Clause grants

Congress the following authority: "To define and punish Piracies

and Felonies committed on the high Seas, and Offences against the

Law of Nations."        U.S. Const. art. I, § 8, cl. 10.             We discuss

below primarily the text that precedes the comma -- i.e., the

authority with respect to "Piracies and Felonies committed on the

high Seas."       That is so because, as we have noted, it is undisputed

in this case that the MDLEA was enacted pursuant to Congress's

authority under the Felonies Clause.             Although the reference to

"Piracies" -- a crime "committed on the high Seas" and appearing

alongside the term "Felonies" -- necessarily plays a role in our

analysis, the separate clause referencing "Offences against the

Law of Nations," which applies to crimes committed both on land

and at sea, sheds no light on the scope of U.S. jurisdiction on

the   high   seas.      We   therefore   focus   solely   on   the    authority

specifically given to Congress over crimes "on the high Seas."

             That focus requires us to determine what the Framers

intended by the words they chose.            In so doing, we seek guidance


                                    - 50 -
on the Framers' understanding of international law principles,

including   international   law   terminology,    from     contemporaneous

sources.    See U.S. Steel Corp. v. Multistate Tax Comm'n, 

, 461-62 & n.12 (1978) (explaining the Framers' separate use of

the terms "treaty," "compact," and "agreement" in Article I of the

Constitution by reference to treatises on international law with

which the Framers would have been familiar); Waring v. Clarke, 

, 441 n.1 (1847) (stating that "[t]he Constitution . . .

refers to the law of nations for the meaning of" the terms

"admiralty" and "maritime," and thus interpreting those terms in

light of their meaning in international law); see also Zivotofsky

ex rel. Zivotofsky v. Kerry, 

 (2015) (looking to

"prominent international scholars" from "the time of the founding"

to elucidate the meaning of the Reception Clause, Article II,

section 3, of the Constitution).

            Just as it does today, at the time the Framers were

drafting    the   Constitution   the   term   "Felonies"    meant   serious

crimes, such as treason, murder, arson, burglary, robbery, and

rape.   See Blackstone, supra, at *94; 2 Timothy Cunningham, A New

and Complete Law Dictionary 23-28 (3d ed. 1783).               Before the

Constitution became the governing law, all such crimes, whether

committed on land or at sea, were defined by state statutes or

state common law and punished in state courts.               In the only

statement at the Constitutional Convention regarding the inclusion


                                  - 51 -
of the term "Felonies," James Madison explained that, "[i]f the

laws of the states were to prevail on [the meaning of "Felonies"],

the citizens of different states would be subject to different

punishments for the same offence at sea.             There would be neither

uniformity nor stability in the law."              5 Debates on the Federal

Constitution 437 (Jonathan Elliot ed., 2d ed. 1836).             As voiced by

Madison, then, the constitutional drafters recognized the need to

create a uniform system of crimes and punishments on the high seas

that would apply to all U.S. citizens.               There was no mention,

however, of conduct committed by foreigners on foreign vessels.

           Nonetheless, the independent inclusion of "Piracies" in

the Define and Punish Clause provides a clue to the Framers' intent

regarding U.S. jurisdiction over felonies committed on foreign

vessels.    The separate references to "Piracies" and "Felonies"

inescapably reflects the Framers' view that Congress's power over

each   category   was    meant   to    be    distinct.   See   generally   The

Federalist No. 42, at 233 (James Madison) (E.M. Scott ed., 1898)

(discussing the necessity of defining each term). That distinction

has its origin in international law.

           Piracy,      as   defined    by     international   law   --   i.e.,

"robbery upon the sea," United States v. Smith, 

, 162




                                      - 52 -
(1820)40 -- is a crime of "universal jurisdiction,"41 meaning that

it can be punished by any country no matter where it is committed

or by whom. At the time the Constitution was drafted, this feature

of piracy under international law was well established.       See




     40 A more expansive definition of the universal crime of
piracy, updated to include the realm of aviation, is as follows:
               Piracy includes any illegal act of
          violence, detention or depredation committed
          for private ends by the crew or passengers of
          a private ship (or aircraft) against another
          ship (or aircraft) or persons or property on
          board it, on (or over) the high seas[.]

R.R. Churchill & A.V. Lowe, The Law of the Sea 209-10 (3d ed.
1999).
     41 As stated in modern international law, the doctrine of
universal jurisdiction provides that "a nation may prosecute
certain serious offenses even though they have no nexus to its
territory or its nationals, and no impact on its territory or its
citizens."    Cardales-Luna, 

 (Torruella, J.,
dissenting); see also Restatement (Third) of Foreign Relations Law
of the United States § 404 (1987) (noting that "[a] state has
jurisdiction to define and prescribe punishment for certain
offenses recognized by the community of nations as of universal
concern," even where there is no nexus between the offense and the
state).    Crimes may be universal jurisdiction offenses if they
are "contrary to a peremptory norm of international law" and are
"so serious and on such a scale that they can justly be regarded
as an attack on the international legal order."       Kontorovich,
Beyond the Article I Horizon, supra, at 1224 n.228 (quoting
Universal Jurisdiction: National Courts and the Prosecution of
Serious Crimes under International Law 178-79 (Stephen Macedo ed.,
2004)). At present, in addition to piracy, the crimes generally
recognized as subject to universal jurisdiction are the "slave
trade, attacks on or hijacking of aircraft, genocide, war crimes,
and perhaps certain acts of terrorism." See Restatement (Third)
of Foreign Relations Law of the United States § 404.          Drug
trafficking is not recognized as a universal jurisdiction crime.
Aybar-Ulloa, 

.


                             - 53 -
Blackstone, supra, at *71 (stating that "every community has a

right" to punish piracy because it "is an offense against the

universal law of society"); 1 James Kent, Commentaries on American

Law 174 (1826) (stating that "piracy, under the law of nations, is

an offence against all nations, and punishable by all").        As

Justice Story explained in an early piracy case:

          Pirates may, without doubt, be lawfully
          captured on the ocean by the public or private
          ships of every nation; for they are, in truth,
          the common enemies of all mankind, and, as
          such, are liable to the extreme rights of war.
          And a piratical aggression by an armed vessel
          sailing under the regular flag of any nation
          may be justly subjected to the penalty of
          confiscation for such a gross breach of the
          law of nations.

The Marianna Flora, 

 (1825); see also

Cardales-Luna, 

 (Torruella, J., dissenting) ("Until

recently, piracy was the only crime which was punishable by all

nations . . . ."); United States v. Yousef, 

 (2d

Cir. 2003) ("The class of crimes subject to universal jurisdiction

traditionally included only piracy.").

          That the Framers understood the term "Piracies" to refer

to the specific offense subject to universal jurisdiction is

supported by their statements describing piracy as a term borrowed

from international law.   For example, at the Virginia Convention,

James Madison explained that "Piracies" was "[a] technical term of

the law of nations." 3 Farrand's Records, supra, at 332.   Thus, by



                              - 54 -
separating    the   term   "Piracies"   from    "Felonies,"   the   Framers

plainly intended to refer to the specific crime that, under

international law, could be punished by Congress even when it was

committed by foreign nationals on foreign vessels.

           Just as plainly, then, the phrase "Felonies committed on

the high Seas" was intended to reference other types of serious

crimes committed on vessels.      At the time, it was a well-accepted

principle of international law that countries could enact statutes

criminalizing conduct on the high seas other than piracy, but only

as to a given country's own nationals or on vessels over which the

country could exercise jurisdiction pursuant to international law.

See Blackstone, supra, at *71 (describing acts that would be

punished as felonies only if committed by an English "subject" at

sea); Letter from Thomas Jefferson to Edmond Charles Genet (June

17, 1793) (explaining that a country's jurisdiction over crimes

such as murder "on the high seas . . . reaches its own citizens

only"); William Rawle, A View of the Constitution of the United

States of America 107 (2d ed. 1829) (explaining that Congress's

power to punish felonies applies to anyone "except the citizens or

subjects of a foreign state sailing under its flag," but that

piracy is "punishable in our courts, and in the courts of all

nations"     (emphasis     added));     Henry    Wheaton,     Elements   of

International Law 164 (Richard Henry Dana, Jr., ed., 8th ed. 1866)

(observing that countries could enact laws punishing conduct at


                                 - 55 -
sea, but such conduct could "only be tried by that State within

whose territorial jurisdiction" or "on board of whose vessels, the

offence thus created was committed").

            Confusingly, these other serious crimes, which would be

denominated felonies if committed on land, were often referred to

as "piracies" when committed on the high seas, even though they

were not "Piracy" as defined by international law.             See Wheaton,

supra,    (explaining   that   "[t]here    are   certain    acts   which   are

considered piracy by the internal laws of a State, to which the

law of nations does not attach the same signification"); Hon. John

Marshall, Speech Delivered in the House of Representatives (Mar.

7, 1800), at 10 ("A statute may make any offence piracy, committed

within the jurisdiction of the nation passing the statute, and

such offence will be punishable by that nation."); Kent, supra,

(explaining that, under international law, "[t]he statute of any

government may declare an offence committed on board its own

vessels to be piracy, and such an offence will be punishable

exclusively by the nation which passes the statute").                 As one

scholar explains, the term piracy "had a popular meaning of serious

or capital offense on the high seas," Eugene Kontorovich, The

"Define    and   Punish"   Clause    and    the    Limits     of   Universal

Jurisdiction, 103 Nw. L. Rev. 149, 166 (2009), and the term was

thus used colloquially to refer to any felony committed at sea,

see John Marshall Speech at 10 ("It is by confounding general


                                  - 56 -
piracy with piracy by statute, that indistinct ideas have been

produced, respecting the power to punish offences committed on the

high seas.").

            The Framers' separation of "Piracies" and "Felonies" in

the Define and Punish Clause avoids this confusion and reserves

the precise meaning of "Piracy" under international law for that

specific crime.     The Framers' use of the separate terms "Piracies"

and "Felonies" thus manifests an intent to distinguish between

crimes with different jurisdictional limits under international

law:    classic   piracy,   which   can     be    punished   no   matter    where

committed or by whom, and Felonies, which can be punished only if

committed   by    U.S.   nationals42   or    on    vessels   subject   to   U.S.

jurisdiction under international law.             As noted in the Aybar-Ulloa

concurrence, "the United States itself early on took the position

before the Supreme Court that the Define and Punish Clause" "is


        As stated supra, we do not address here the MDLEA's
       42

application to U.S. citizens and resident aliens. However, the
sources quoted above indicate that the Framers would have
understood the Felonies Clause to permit U.S. authorities to
exercise jurisdiction over U.S. nationals on foreign vessels in at
least some circumstances. See Skiriotes v. Florida, 

 (1941) (stating that "the United States is not debarred by any
rule of international law from governing the conduct of its own
citizens upon the high seas or even in foreign countries when the
rights of other nations or their nationals are not infringed");
United States v. Kaercher, 

 (1st Cir. 1983) (per
curiam) (quoting the Restatement of Foreign Relations Law of the
United States for the proposition that "[a] state has jurisdiction
to prescribe a rule of law . . . attaching legal consequences to
conduct of a national of the state wherever the conduct occurs"
(alteration and omission in original)).


                                    - 57 -
impliedly limited by the law of nations in ways that constrain

Congress's authority to rely on that Clause to subject foreign

nationals to our criminal laws for conduct that they engage [in]

while they are on foreign vessels -- even when those vessels are

on the high seas." 

 n.7, 15 (Barron, J., concurring);

see 

 at 16 n.7 (quoting the argument of Mr. Blake on behalf of

the United States in United States v. Palmer, 

 (1818): "A felony, which is made piracy by municipal

statutes, and was not such by the law of nations, cannot be tried

by the courts of the United States, if committed by a foreigner on

board a foreign vessel, on the high seas; because the jurisdiction

of the United States, beyond their own territorial limits, only

extends to the punishment of crimes which are piracy by the law of

nations.").

          3. Jurisdiction on the High Seas under International Law

          Given   the   Framers'   clear   intention   to   draw   a

jurisdictional distinction between "Piracies" and "Felonies," the

question of when a vessel sailing on the high seas may be subject

to U.S. jurisdiction under international law -- i.e., the question

at the heart of this case -- has constitutional significance.      It

is a bedrock principle of the international law of the sea,

recognized long before the founding of this country, that "all

nations have an equal and untrammelled right to navigate on the

high seas."   Marino-Garcia, 

; see also United


                              - 58 -
States v. Maine, 

, 96 n.11 (1986) (explaining that

"since the days of Grotius, the principle of the freedom of the

high seas found an ever wider currency" and "crystallized into a

universally   accepted   principle   of   international   law"   by   "the

beginning of the nineteenth century" (quoting Yehuda Z. Blum,

Historic Titles in International Law § 61, at 242-43 (1965)));

Hugo Grotius, The Freedom of the Seas 44 (Ralph V.D. Magoffin

trans., 1916) ("It is clear . . . that he who prevents another

from navigating the sea has no support in law."); United Nations

Convention on the Law of the Sea ("UNCLOS") art. 90, Dec. 10, 1982,

1833 U.N.T.S. 397.43     To ensure this right of free navigation,


     43 Although the Senate has not ratified the UNCLOS, it was
signed by the President and is generally recognized by the United
States as reflecting customary international law, i.e., universal
practice.   See United States v. Alaska, 

, 588 n.10
(1992) (acknowledging the U.S. government's position that the
UNCLOS provisions are part of customary international law); see
also Aybar-Ulloa, 

 n.2 (citing the UNCLOS "as evidence
of the customs and usages of international law"); United States v.
Hasan, 

 (E.D. Va. 2010) ("[T]he United
States has consistently accepted UNCLOS as customary international
law for more than 25 years."). Moreover, "many of the provisions
of the [UNCLOS] follow closely provisions in the 1958 conventions
to which the United States is a party and which largely restated
customary law as of that time." Restatement (Third) of Foreign
Relations Law of the United States, Part V, Introductory Note; see
also Mayagüezanos por la Salud y el Ambiente v. United States, 

, 304 n.14 (1st Cir. 1999) (referring to the "UNCLOS only
to the extent that it incorporates customary international law,"
and noting that, as a signatory, "the United States 'is obliged to
refrain from acts that would defeat the object and purpose of the
agreement'" (quoting Restatement (Third) of Foreign Relations Law
of the United States § 312(3))). The UNCLOS provisions defining
a stateless vessel discussed infra have long been part of the
international law of the sea and are largely identical to those in


                                - 59 -
"international law generally prohibits any country from asserting

jurisdiction over foreign vessels on the high seas," and "vessels

are normally considered within the exclusive jurisdiction of the

country whose flag they fly."44   Marino-Garcia, 

;

see also Aybar-Ulloa, 

; John Marshall Speech at 5

(stating that "the opinion of the world is, that a fleet at sea,

is within the jurisdiction of the nation to which it belongs").

          To preserve this system of flag-state jurisdiction,

"every vessel must sail under the flag of one and only one state;

those that sail under no flag . . . enjoy no legal protection."

Matos-Luchi, 627 F.3d at 5; see also, e.g., Aybar-Ulloa, 

 (noting that "international law renders stateless vessels

'susceptible to the jurisdiction of any State'" (quoting Barnes,

supra, at 314)); United States v. Pinto-Mejia, 

(2d Cir. 1983) (explaining that "a stateless vessel, which does

not sail under the flag of one state to whose jurisdiction it has

submitted, may not claim the protection of international law and

does not have the right to travel the high seas with impunity");

United States v. Rubies, 

 (9th Cir. 1979) ("'In


the 1958 Convention on the High Seas, which has been ratified by
the United States. See supra, arts. 5 & 6.
     44 Although the nationality of a vessel is often referred to
as its "flag," there is no requirement that a vessel fly a physical
flag to maintain its nationality. See Matos-Luchi, 627 F.3d at 5.
Rather, "[s]hips have the nationality of the State whose flag they
are entitled to fly." UNCLOS art. 91, § 1 (emphasis added).


                              - 60 -
the interest of order on the open sea, a vessel not sailing under

the maritime flag of a State enjoys no protection whatever, for

the freedom of navigation on the open sea is freedom for such

vessels only as sail under the flag of a State.'" (quoting Lassa

Oppenheim, International Law 546 (7th ed. 1948))).                Therefore, it

has long been understood that the United States -- and any other

country    --   may      exercise   jurisdiction     over   vessels   that    are

considered stateless under international law.               We confirmed that

understanding       in    Aybar-Ulloa.      See,    e.g.,   

("[S]tateless vessels are treated as subject to the exercise of

authority by any nation."); see also, e.g., Matos-Luchi, 627 F.3d

at 6 (noting that "international law . . . treats the 'stateless

vessel' concept as informed by the need for effective enforcement,"

and, hence, "a vessel may be deemed 'stateless,' and subject to

the enforcement jurisdiction of any nation on the scene, if it

fails to display or carry insignia of nationality and seeks to

avoid national identification"); Andrew W. Anderson, Jurisdiction

over Stateless Vessels on the High Seas: an Appraisal Under

Domestic and International Law, 

, 337

(1982)    ("[T]he     extension     of   United    States   jurisdiction     over

stateless vessels seems not only to be a reasonable claim but

completely consistent with both customary and treaty international

law.").




                                      - 61 -
           These general principles of jurisdiction on the high

seas are not disputed in this case, and, indeed, the Supreme Court

applied these principles in the decades immediately following the

Constitution's adoption.     In 1790, Congress passed a law making

murder and robbery committed by "any person" on the high seas

punishable under U.S. law.       See Palmer, 

.

It was an open question, however, whether the statute extended to

conduct   by   foreigners   on    foreign   vessels.   When   he   was   a

congressman, John Marshall argued that the Define and Punish Clause

           can never be construed to make to the
           government a grant of power, which the people
           making it, did not themselves possess. It has
           already been shown that the people of the
           United States have no jurisdiction over
           offences, committed on board a foreign ship,
           against a foreign nation. Of consequence, in
           framing a government for themselves, they
           cannot have passed this jurisdiction to that
           government.

John Marshall Speech at 24-25.

           Not surprisingly, then, the Supreme Court in United

States v. Palmer, in an opinion written by now Chief Justice

Marshall, held that the statute did not extend U.S. jurisdiction

to foreigners on foreign vessels for the common law form of

robbery, as distinguished from classic piracy.         See 

.      The Court reiterated its holding on the

statute's reach    two years later, concluding that it did not

criminalize the murder of a foreigner on a foreign vessel on the



                                  - 62 -
high seas because Congress knew it "had no right to interfere" in

such cases.     Furlong, 

; see also 

 (observing that "punishing [murder] when committed within the

jurisdiction, or, (what is the same thing,) in the vessel of

another nation, has not been acknowledged as a right, much less an

obligation").     By contrast, the Supreme Court recognized the

classic form of piracy as "a crime within the acknowledged reach

of the punishing power of Congress" even when "committed by a

foreigner upon a foreigner in a foreign ship," 

, and

noted in other cases that "[m]urders committed by and against

foreigners on stateless vessels . . . could be prosecuted in the

United States," Aybar-Ulloa, 

 (citing United States

v. Klintock, 

 (1820) and United States

v. Holmes, 

 (1820)).45

          Thus, in light of these well-established limitations on

Congress's ability to criminalize the conduct of foreign nationals




     45As noted above, the concurring opinion in Aybar-Ulloa also
reports the historical support, in caselaw and commentary, for the
contention that Congress lacks authority under the Define and
Punish Clause to punish foreign nationals for conduct committed on
foreign vessels, "even when those vessels are on the high seas."

-16 & n.7 (Barron, J., concurring); see also 

 (discussing the cases "decided just decades after the
Constitution's ratification" that "dealt with the United States'
power to prosecute defendants of a range of citizenships and
circumstances who shared the attribute of having been indicted in
our country pursuant to our criminal justice system for murder,
robbery, or other wrongdoing on the high seas").


                                - 63 -
aboard foreign vessels on the high seas,46 the question that arises

when the United States seeks to impose its law on foreigners on

the high seas is how to identify a vessel that is not within any

other country's jurisdiction -- potentially exposing those aboard

to every country's jurisdiction.47         In other words, when may a

vessel be characterized as stateless?        Stateless vessels do not

appear to have been a primary focus at the time of the Framers,

and we have found no explicit statements in their deliberations on

when a vessel should be deemed stateless. That silence, of course,

is unsurprising, given the focus on avoiding improper intrusions

into the affairs of foreign nations.

              As we have concluded, however, there can be no doubt

that    the    Constitution's   drafters    intended   that   Congress's




        There are, of course, exceptions to the broad principle
       46

that Congress cannot extend U.S. criminal jurisdiction to crimes
like common law robbery or murder committed by foreigners against
foreigners on foreign vessels.      For example, a country may
prosecute such crimes with the consent of the foreign nation. See
Matos-Luchi, 627 F.3d at 7; see also 

(c)(1)(C).
But these exceptions are not pertinent here.
       We use the word "potentially" because we declined in Aybar-
       47

Ulloa to decide "whether the United States may prosecute a foreign
citizen engaged in drug trafficking on a stateless vessel where
the United States never boarded and seized the vessel." 

. We note, in addition, the observation in the Aybar-Ulloa
concurrence that the Third and Fourth Restatements of Foreign
Relations Law of the United States do not "establish that the
prevailing view of the law of nations is that the interdicting
country acquires the same territorial jurisdiction over the
[stateless] vessel's occupants as it acquires over the vessel
itself." 

 (Barron, J., concurring).


                                 - 64 -
authority   under      the    Define     and    Punish      Clause,    including      the

Felonies portion of it, be constrained by currently applicable

international law whenever Congress invokes that Clause to assert

its authority over foreign nationals and their vessels on the high

seas.   The Framers sought to ensure that Congress would respect

the sovereignty of other nations, and the limits placed on the

prosecution      of    other    countries'           nationals    is    an    essential

component     of      the    international       system      of    mutual      respect.

Necessarily, then, that constraint applies when Congress passes

legislation deeming vessels on the high seas stateless.                          If the

Constitution instead permitted Congress to define a vessel as

stateless in any way it wished, there would be a risk that Congress

could contravene international norms determining when a country

may prosecute felonies committed by foreign nationals on the high

seas.    It therefore follows that the Felonies Clause requires

Congress to abide by international law principles in defining

statelessness.        We thus review those principles.

            4.     Statelessness under International Law

            International         law   allows       each   nation     to    decide   for

itself the process through which it will grant its nationality to

a vessel. See Lauritzen v. Larsen, 

 (1953) ("Each

state   under      international        law    may    determine      for     itself   the

conditions on which it will grant its nationality to a merchant

ship,   thereby       accepting    responsibility           for   it   and    acquiring


                                        - 65 -
authority over it."); UNCLOS art. 91, § 1 ("Every State shall fix

the conditions for the grant of its nationality to ships, for the

registration of ships in its territory, and for the right to fly

its flag."); 5 J.H.W. Verzijl, International Law in Historical

Perspective 146 (1972) (describing an 1801 proclamation by the

King of England regarding the conditions under which merchant ships

may fly the British flag, and noting "[t]he general principle

. . . that it is within the domestic jurisdiction of any State

. . . to determine on what conditions it will allow a sea-going

vessel to fly its flag and thus grant her its 'nationality'").

The simplest definition of a stateless vessel under international

law is thus a vessel that has not been granted nationality by any

state.     Pursuant    to   that     definition,      a    vessel   will    lack

nationality, for example, "if no state has ever authorized [the

vessel]   to   fly    its   flag,    if   a   state       has   cancelled   its

authorization, or if the political entity that authorized a ship

to fly its flag is not recognized as an international person."

Rosero, 

; see also 

 ("[A] vessel is without

nationality if it is not authorized to fly the flag of any

state."); Matos-Luchi, 627 F.3d at 16 (Lipez, J., dissenting)

("Under international law, a stateless vessel is simply one that

does not have a valid grant of nationality from any country.").

          Authorities encountering a vessel on the high seas would

not be aware of some of these circumstances -- e.g., if a state


                                    - 66 -
has cancelled a vessel's registration -- and thus will be unable

to definitively determine nationality by sight even if a vessel is

flying    a   flag.       Nonetheless,    international     law    recognizes   a

presumption of nationality in the flag-flying situation, among

others.       We   have    noted   that   "[b]y   custom,   a     vessel   claims

nationality by flying the flag of the nation with which it is

affiliated or carrying papers showing it to be registered with

that nation."      Matos-Luchi, 627 F.3d at 5 (citing Lassa Oppenheim,

International Law § 261, at 594-96 (H. Lauterpacht ed., 8th ed.

1955)); see also United States v. Bustos-Guzman, 

 (11th Cir. 1982) (per curiam) (noting that flying a flag is

generally "prima facie proof" of nationality under international

law); The Chiquita, 

 (5th Cir. 1927) ("The flag

under which a merchant ship sails is prima facie proof of her

nationality.").

              Absent a flag or papers, "a vessel may also traditionally

make an oral claim of nationality when a proper demand is made."

Matos-Luchi, 627 F.3d at 5; see also Aybar-Ulloa, 

(quoting Matos-Luchi, 627 F.3d at 5); United States v. Obando, 

 (11th Cir. 2018) (Black, J., specially concurring)

(noting that, under "longstanding principles of admiralty law,"

the master "speak[s] on behalf of the ship" and must be the one to

make a verbal claim of nationality); The Little Charles, 

 (Marshall, Circuit Justice, C.C. Va. 1818) ("The


                                     - 67 -
vessel acts and speaks by the master."); Anderson, supra, at 341

(noting that a vessel may claim nationality "by showing its flag,

presenting its documents, or making some other outward or oral

claim to a nationality" (emphasis added)).                  The MDLEA itself

recognizes this form of asserting nationality, stating that "[a]

claim of nationality or registry under this section includes

. . . a verbal claim of nationality or registry by the master or

individual in charge of the vessel."          

(e)(3).

             International    law      also   recognizes         two   specific

circumstances in which a vessel may be deemed stateless regardless

of its actual status and absent any effort to determine its

nationality: when the vessel refuses to claim any nationality or

when it claims more than one nationality.              See Matos-Luchi, 627

F.3d at 6-7 (stating that "a vessel may be deemed 'stateless' . . .

if it fails to display or carry insignia of nationality and seeks

to   avoid    national    identification"        by   "refus[ing],      without

reasonable excuse, to reveal its" nationality (quoting Meyers,

supra, at 322) (internal quotation marks omitted)); UNCLOS art.

92, § 2 (stating that "[a] ship which sails under the flags of two

or more States . . . may be assimilated to a ship without

nationality");    The    Commander's    Handbook      on   the   Law   of   Naval

Operations                          ¶ 3.11.2.4                          (2017),

https://www.gc.noaa.gov/pdfs/CDRs_HB_on_Law_of_Naval_Operations_

AUG17.pdf (stating that "[a] vessel may be assimilated to a vessel


                                    - 68 -
without nationality," inter alia, "when the vessel makes multiple

claims of nationality . . . or the master's claim of nationality

differs from the vessel's papers").48

            Hence, whether authorities are seeking to ascertain

nationality in the first place             --    by examining documents or

eliciting   a   verbal   claim   --   or    to    resolve   a    concern   about

nationality that was declared by means of a flag, they may need

close contact with the vessel and its master.                   It is therefore


     48The 2017 version of the Commander's Handbook -- applicable
to the U.S. Navy, Marine Corps, and Coast Guard -- also states
that a vessel may be "treated as one without nationality" when,
among other factors, it displays no "identifying characteristics,"
when -- consistent with § 70502(d)(1) -- the master makes no claim
of nationality or registry, or when "[t]he claim of registry or
the vessel's display of registry is either denied or not
affirmatively and unequivocally confirmed by the State whose
registry is claimed."    Commander's Handbook ¶ 3.11.2.3 (2017),
supra; see also id., References 4 (listing MDLEA, 

). Interestingly, the Handbook's previous version,
in effect when appellants were detained, did not include the
failure-to-verify scenario that mirrors § 70502(d)(1)(C) of the
MDLEA. Rather, its list of characteristics of a stateless vessel
all relied on inconsistencies in a vessel's presentation of
nationality to observers or the absence of, or refusal to provide,
identification. See Commander's Handbook ¶ 3.11.2.4 (2007),
https://www.marines.mil/Portals/1/Publications/MCTP%2011-
10B%20(%20Formerly%20MCWP%205-12.1).pdf?ver=2017-07-11-151548-
683 (providing "a partial list of factors that should be considered
in determining whether a vessel is appropriately assimilated to
stateless status: (1) No claim of nationality; (2) Multiple claims
of nationality; (3) Contradictory claims or inconsistent
indicators of nationality (e.g. master's claim differs from
vessel's papers; homeport does not match nationality of flag); (4)
Changing flags during a voyage; (5) Removable signboards showing
different vessel names and/or homeport; (6) Absence of anyone
admitting to be the master; displaying no name, flag, or other
identifying   characteristics;    and   (7)   Refusal    to   claim
nationality").


                                  - 69 -
understood that international law's so-called "right of visit"

permits authorities to inquire, board, and conduct a limited search

"designed to elicit information about the vessel's identification

and registration."             Cuevas-Esquivel, 

; see also

Aybar-Ulloa, 

 (recognizing that a "clearly-marked law

enforcement ship of any state may board [a private ship] . . . if

there       is   reason   to    suspect   that    the   ship   . . . is    without

nationality" (quoting Restatement (Third) of Foreign Relations Law

of the United States § 522(2)(b) (1987)) (omissions in original));

United States v. Cortes, 

 (5th Cir. 1979) (stating

that, under international law, "stateless vessels are subject to

this    type     of   examination").49      The    question    in   this   appeal,

addressed in Section V.C infra, is whether international law




        The "right of visit" under international law allows a
       49

"warship" (which would include a law enforcement ship like the
Coast Guard vessel here) to stop and question a foreign ship if
"there is reasonable ground for suspecting that the ship is engaged
in piracy," slave trading, or illegal broadcasting, "is without
nationality," or, although flying a foreign flag, is actually of
the same nationality as the warship.       UNCLOS art. 110, § 1.
However, the right of visit does not provide an independent ground
for exercising jurisdiction over a vessel, and certainly does not
allow a state to apply its domestic laws to those aboard that
vessel.    Rather, it is simply a mechanism for a state to
investigate suspected wrongdoing and then take actions within its
authority under international law.    See, e.g., Penelope Mathew,
Address - Legal Issues Concerning Interception, 

, 224-25 (2003) (discussing the limited nature of the right
of visit and noting that "a State would have to rely on some
positive basis of jurisdiction . . . to exercise jurisdiction over
persons on a stateless ship").


                                       - 70 -
permits Congress to dictate the results of such an inquiry as

provided in § 70502(d)(1)(C) of the MDLEA.

            5. Summary: The Felonies Clause and Stateless Vessels

            Our review of the law governing jurisdiction on the high

seas thus reveals clear signs in multiple sources -- the historical

record, the well-established perspective in the late eighteenth

century on the role of individual nations in the international

sphere, and contemporaneous legal precedent -- that the Framers'

invocation of international law terminology in the Define and

Punish Clause was deliberate. Seeking to ensure their new nation's

compliance with international law, the Framers invoked principles

drawn from that law in drafting the Define and Punish Clause

generally and the Felonies Clause specifically.              In particular,

they knew the distinction in international law between "Piracies,"

which can be punished by any country wherever they occur, and other

serious crimes on the high seas, which can be punished by a country

only when committed by individuals subject to its jurisdiction.

The Framers' goal of incorporating respect for international norms

into the federal system thus makes clear that, under the Felonies

Clause, Congress's authority to set the boundaries of domestic law

on   the   high    seas   must   be   consistent   with   international   law

principles.       Pursuant to those principles, the key to determining

whether Congress can apply domestic law to foreign nationals on a

non-U.S. vessel on the high seas ordinarily will depend on whether


                                      - 71 -
international law would deem the vessel to be "without nationality"

-- i.e., stateless.     Finally, international law recognizes that an

oral claim by the vessel's master constitutes prima facie proof of

the vessel's nationality.

            With that understanding of the applicable law, we turn

to the question of whether Congress exceeded its power to "define

and punish . . . Felonies committed on the high Seas" in the

challenged provision of the MDLEA.

C.     Constitutionality of § 70502(d)(1)(C)

            The MDLEA reflects Congress's objective of addressing,

to the full extent of its authority, the scourge of drugs entering

the United States from abroad.        See Matos-Luchi, 627 F.3d at 11

(Lipez, J., dissenting) (noting that the MDLEA and its predecessor,

the Marijuana on the High Seas Act, 

 Stat.

1159 (1980), manifest Congress's objective to "give the Justice

Department the maximum prosecutorial authority permitted under

international law" (quoting S. Rep. 96-855, at 2 (1980))); 

 ("The MDLEA was responding to repeatedly frustrated efforts to

prosecute maritime drug trafficking.").           Undoubtedly mindful of

the   prohibition     against   applying   domestic   law   to   foreigners

traveling on foreign vessels on the high seas, Congress plainly

sought in the MDLEA provision defining a stateless vessel to reach

as    broadly   as   possible   through    an   expansive   definition   of

statelessness.       The statute, however, can reach no farther than


                                  - 72 -
the authority granted to Congress by the Felonies Clause, which,

as we have determined, is constrained by the norms of international

law.

            As detailed above, the MDLEA provides three descriptions

for a "vessel without nationality" in § 70502(d)(1). See 

(d)(1).50       Two are clearly consistent with international

law: when the nation whose registry is claimed denies the claim,

 § 70502(d)(1)(A), and when the individual in charge of a vessel

fails to make a claim of nationality or registry for the vessel

upon    request   of    an   authorized       United   States   officer,      id.

§ 70502(d)(1)(B); see, e.g., Matos-Luchi, 627 F.3d at 6 (involving



        For convenience,
       50                       we    provide     here   the    full   text   of
§ 70502(d)(1):
            In this chapter, the term "vessel without nationality"
            includes --
            (A) a vessel aboard which the master or
            individual in charge makes a claim of registry
            that is denied by the nation whose registry is
            claimed;
            (B) a vessel aboard which the master or
            individual in charge fails, on request of an
            officer of the United States authorized to
            enforce applicable provisions of United States
            law, to make a claim of nationality or
            registry for that vessel; and
            (C) a vessel aboard which the master or
            individual in charge makes a claim of registry
            and for which the claimed nation of registry
            does not affirmatively and unequivocally
            assert that the vessel is of its nationality.

       

(d)(1).


                                     - 73 -
a refusal to make a claim of nationality).      The third definition,

however -- the one at issue here -- allows a vessel to be treated

as stateless where there is a claim of nationality recognized by

international law but the identified country neither confirms nor

denies that claim.     See 

(d)(1)(C).

            This provision thus treats a response that reports only

that the named country is unable to confirm nationality -- or the

country's failure to respond at all to U.S. inquiry -- as evidence

that is equivalent to an outright denial of a master's claim of

nationality    or   registry.   In   other   words,   § 70502(d)(1)(C)

displaces the prima facie showing of nationality that arises from

an oral assertion of nationality or registry -- made in accordance

with international law -- without any affirmative evidence to the

contrary.     See Bustos-Guzman, 

 (referring to the

"prima facie proof" of nationality that arises from flying a flag);

The Chiquita, 

 (same); 

(e) (listing

flying a flag and a verbal claim as alternative methods of making

a claim of nationality).    In so doing, § 70502(d)(1)(C) adds a new

category to the limited circumstances in which international law

deems a vessel stateless (the refusal to claim a nationality,

claiming more than one nationality, and disavowal of a claim of

nationality by the named country).       A response stating only that

the country is unable to confirm nationality, or the country's

failure to provide any response, suffices to nullify even an


                                - 74 -
unequivocal claim of nationality or registry made by the person in

charge of the vessel.

           The government contends that this variation on deeming

a vessel stateless is implicitly, if not explicitly, recognized in

international law.        The government asserts that international law

requires a vessel not only to make a claim of nationality, but

also to "'be in a position to provide evidence of [nationality].'"

Appellee's   Br.    at    29   (quoting      Matos-Luchi,   627     F.3d   at   6).

Consequently,       the      government       proposes,     an      absence      of

"affirmative[] and unequivocal[]" confirmation from the claimed

country   may    properly      be   relied    upon   in   deeming    the   vessel

stateless.      Id. at 36.

           In making this assertion, the government relies heavily

on dicta in Matos-Luchi, a case in which the defendants had

declined to make a claim of nationality in response to a request

from Coast Guard personnel.            See 627 F.3d at 2.51          As we have

described, avoiding national identification is a well-established

basis for deeming a vessel stateless, and it is incorporated into

the MDLEA in § 70502(d)(1)(B).         See supra note 50; see also, e.g.,

Meyers, supra, at 322 ("[A] ship which obscures the cognoscibility

of its allocation repeatedly, deliberately, and successfully may


     51 In Matos-Luchi, when the Coast Guard approached a small
vessel whose crew members were suspected of drug trafficking, the
crew initially fled and, when subsequently apprehended, "declined
to make a claim of nationality" for their vessel. 627 F.3d at 2.


                                     - 75 -
be treated as stateless." (internal quotation marks omitted)).

However, the Matos-Luchi majority went beyond that indisputable

basis for deeming a vessel stateless -- and the facts before it -

- to suggest that an oral declaration of nationality is inadequate

if the vessel's master provides no other evidence of the claimed

nationality.      See 627 F.3d at 6.             Stated without examination of

the issue, the majority's dicta, which is not binding on another

panel,    does    not     support        the   government's        contention      that

international law allows a vessel to be deemed stateless based

solely on the absence of confirming evidence of the master's verbal

claim.    As the government acknowledges, the MDLEA recognizes "a

verbal claim of nationality or registry by the master" as a "claim

of   nationality    or    registry"       equivalent    to    flying       a    flag   or

producing "documents evidencing the vessel's nationality."                             

(e).        Rejecting a verbal claim of nationality based

solely on a lack of substantiating evidence effectively negates

that distinct method for claiming nationality recognized both by

the MDLEA and by international law.

           The government also directly invokes international law

to support its position. In its supplemental brief, the government

cites articles 17(1) and (2) of the United Nations Convention

against   Illicit       Traffic     in    Narcotic    Drugs    and     Psychotropic

Substances,      Dec.    20,   1988,      1582    U.N.T.S.    95    ("UN       Narcotics

Convention"), and article 5(2) of the 1958 Convention on the High


                                         - 76 -
Seas, supra, in arguing that the United States may deem a vessel

stateless     if    neither    its    master      nor   the    claimed   nation

substantiates a verbal claim of nationality.                  Neither of these

sources supports that proposition.             The first cited provision of

the UN Narcotics Convention calls for cooperation "to suppress

illicit traffic by sea, in conformity with the international law

of the sea," id. art. 17(1), and the second states that a party

with "reasonable grounds to suspect that a vessel flying its flag

or not displaying a flag or marks of registry is engaged in illicit

traffic     may    request    the    assistance    of   other    [p]arties   in

suppressing its use for that purpose," id. at 17(2).                      These

principles of cooperation do not speak to the circumstances in

which international law deems a vessel stateless.

            The provision of the 1958 Convention on the High Seas

cited by the government provides that "each state shall issue to

ships to which it has granted the right to fly its flag documents

to that effect." The UNCLOS contains a nearly identical provision,

see UNCLOS art. 91, § 2, and another UNCLOS provision specifically

addresses registration, requiring states to "maintain a register

of ships containing the names and particulars of ships flying its

flag, except those which are excluded from generally accepted

international regulations on account of their small size," id.

art. 94, § 2(a).        The government suggests that such provisions

create an expectation that all vessels will carry documents and


                                      - 77 -
that, if a vessel's master does not substantiate a verbal claim

with   documents         or     other    evidence,       the       claimed    country    of

nationality       "has        accepted       through    its      international      treaty

obligations that the vessel may be deemed stateless."                          Appellee's

Supp. Br. at 16.

            However,           these     treaty        provisions      demanding        that

countries   issue        documents        evidencing       vessel      nationality       say

nothing about when a vessel may be deemed stateless.                          Nor can the

provisions reasonably be construed to provide consent to the

exercise of jurisdiction over a signatory's vessel by all other

signatories   based           solely    on     the    master's     failure    to    produce

documents in support of a claim of nationality.                             Indeed, as we

have noted, consent by the country whose nationality is claimed

provides a separate basis for jurisdiction under the MDLEA, see 

(c)(1)(C), and the statute specifies that consent

"may be obtained by radio, telephone, or similar oral or electronic

means," 

 § 70502(c)(2)(A).                The government's theory of implicit

consent is at odds with this scheme.

            The    government           also    attempts      to    infer    from   treaty

provisions a principle of international law that when a country

both fails to confirm a claim of registration or nationality and

the vessel carries no registration or other identifying documents

the vessel may be deemed stateless.                      This theory conflates two

discrete international law issues.                     Even accepting documentation


                                             - 78 -
requirements as within customary international law, it does not

follow that a country's failure to issue identifying documents or

"maintain a register" renders a vessel stateless when its master

has verbally claimed that country's nationality.                        The relevant

question is not whether the claimed country has satisfied its

obligations under international law.              Rather, the question is what

type of inquiry and response suffices to permit the United States

to    deem    a    vessel    stateless    despite    a    claim    of    nationality

recognized by international law.              On that question, the government

cites no source of international law expressly recognizing a lack

of    documents,        or   the   claimed    country's      failure     to   confirm

nationality (instead of an outright                  denial),     as a    basis for

overcoming the prima facie showing of nationality arising from the

master's oral declaration.

              That lack of support for the government's proposition is

unsurprising.        As we have explained, the master's oral declaration

has    long       sufficed    under    international      law     to    establish     a

presumption        of    nationality.         See,   e.g.,      N.P.    Ready,      Ship

Registrations 3 (3d ed. 1998) ("A vessel may be considered as

possessing        the    nationality     of   a   State   even     though     she    is

unregistered, possesses no documents evidencing that nationality,

nor even flies the flag of that State."); see also Aybar-Ulloa,

 (observing that, "[w]ithout a flag or papers, a

vessel may also traditionally make an oral claim of nationality


                                        - 79 -
when a proper demand is made" (quoting Matos-Luchi, 627 F.3d at

5)).52 That presumption is sensibly overcome by the named country's

express   denial   of   the   claim,   a   scenario    long   embedded   in

international law.

           However, a response stating that the country can neither

confirm nor deny the claim, or the named country's failure to

respond at all, may say very little about the veracity of the

master's assertion of nationality.           Indeed, the inability to

confirm the claim may have more to do with the responding country's

bureaucracy than with the vessel's status.            The facts in United

States v. Hernandez, 

 (11th Cir. 2017), graphically

illustrate the problem with § 70502(d)(1)(C).           The captain of a

vessel told Coast Guard officers that his boat was registered in

Guatemala -- a truthful claim -- and he and the other three crew


     52 In addition to the traditional methods of claiming
nationality discussed above -- flying the flag, presenting
documents, and oral declaration -- authorities may in some
instances look to the nationality of the vessel's owner.      See,
e.g., The Chiquita, 

 ("If [a vessel] is not properly
registered, her nationality is still that of her owner.").
However, whether the owner's nationality establishes that of the
vessel will depend on the practice of the particular country. As
discussed above, "a State is absolutely independent in framing the
rules concerning the claim of vessels to its flag."      Oppenheim
(8th ed.), supra, at 595; see also id. (noting that Great Britain
"allow[s] only such vessels to sail under [Great Britain's] flags
as are the exclusive property of their citizens or corporations
established on their territory," while "[o]ther [countries] allow
vessels which are the property of foreigners" to do so); Churchill
& Lowe, supra, at 213 n.19 (noting that a country may not register
small ships but may "regard such ships as having its nationality
if they are owned by its nationals").


                                 - 80 -
members all identified themselves as Guatemalan citizens.        Id. at

1297.      Indeed, at some point, Guatemalan registration documents

were found on the vessel.       Id.   Nonetheless, when asked by the

Coast Guard to confirm the registry claim, the government of

Guatemala responded that it could neither confirm nor deny it.

Id.     Although the vessel plainly was not stateless, the court

rejected the defendants' challenge to their convictions under the

MDLEA because Guatemala had not "'affirmatively and unequivocally

assert[ed]'     the   ship's   registry."    Id.   at   1299   (quoting

§ 70502(d)(1)(C)).53       In other words, the vessel was deemed


      53The defendants in Hernandez contended that jurisdiction
under the MDLEA was improper because their vessel was in fact
registered and because the Coast Guard had identifying information
about their vessel "that would easily have confirmed its registry,"
but "failed in bad faith to convey that information" to the
Guatemalan government. 

.        In rejecting those
contentions, the court observed that "[t]he MDLEA does not state
what information the United States must convey to the foreign
government during its communication, and it does not state that
actual    registry   overrides    the    [Department   of    State]
certification's proof of statutory statelessness." 

       "MDLEA
statelessness," the court explained, "does not turn on actual
statelessness, but rather on the response of the foreign
government."   

   The court further observed that, given the
MDLEA's "clear terms" deeming their vessel stateless, "any
diplomatic consequences of the criminal prosecution" -- including
any violation of international law -- were the responsibility of
the executive branch and not a basis for undoing the convictions.

.
     One defendant in Hernandez also argued "that the MDLEA is an
unconstitutional assertion of Congressional power because it
reaches stateless vessels on the high seas without a proven nexus
to the United States" -- an argument rejected there as foreclosed
by Eleventh Circuit precedent. 

. The Hernandez
defendants did not make the argument asserted here that
§ 70502(d)(1)(C) is unconstitutional because Congress acted beyond


                                 - 81 -
"stateless" even when verification of its nationality should have

been easily accomplished.

             Moreover, where -- as in Hernandez and here -- the

master's oral declaration of nationality is consistent with the

citizenship or nationality of all individuals aboard the vessel,

the declaration is particularly forceful.               To reject the master's

declaration of nationality in such circumstances based solely on

the    claimed   country's     failure        to     provide   affirmative   and

unequivocal confirmation -- or its failure to respond at all --

would eviscerate a method long accepted for identifying a vessel's

nationality under international law.               We cannot infer displacement

of    that   method   merely   based     on    treaty     provisions   imposing

obligations on signatory countries to register vessels or issue

other documents.54

             That is not to say that the government's emphasis on

registration or documentary evidence of nationality is wholly

misplaced.     International law does, in general, promote a system


its authority under the Felonies Clause in defining a vessel
without nationality to include a vessel whose master makes a verbal
claim of nationality that is not affirmatively and unequivocally
confirmed by the identified country.
       Importantly, § 70502(d)(1)(C) on its face applies not only
       54

to verbal claims of nationality, but to any claim of registration
or nationality, even one based on documentation. By its terms,
therefore, it allows the United States to reject a claim of
registration or nationality that is supported by documentary
evidence based solely on an equivocal response, or no response at
all, from the identified country.


                                  - 82 -
of registration.55   It is reasonable to expect that registered

vessels would have documents onboard, and, if not, that the claimed

country of nationality would be able to easily confirm a legitimate

claim by checking its registry.   However, not all vessels must be

registered.   Small vessels are excluded from the UNCLOS registry

requirement, see UNCLOS art. 94, § 2(a), perhaps because some

countries typically do not register small vessels -- whether

defined by length or by tonnage.       In the United States, for

example, the registration of smaller boats is generally left to

individual states.   See 

(b) (providing that "[a]

vessel of less than 5 net tons may engage in a trade without being



     55As we recognized in Aybar-Ulloa, it is important that some
country exercise jurisdiction over a vessel. See 

.
A flag state
          has    several     responsibilities     [under
          international     law],     including      the
          responsibility to ensure that its ships comply
          with domestic and international law and
          regulations.   . . .   Most notably, a state
          must exercise "jurisdiction and control [over
          its fleet] in administrative, technical, and
          social matters."    Control includes ensuring
          that ships are seaworthy and comply with
          relevant labor regulations and criminal laws.

Allyson Bennett, Note, That Sinking Feeling: Stateless Ships,
Universal   Jurisdiction,   and   the   Drug   Trafficking   Vessel
Interdiction Act, 

, 439 (2012) (second
alteration in original) (footnotes omitted) (citing various
provisions of the UNCLOS); see also Purchase of Ships of
Belligerents by Neutrals, 6 Op. U.S. Att'y Gen. 638, 640 (1854)
("The law of nations and common sense combine to require that every
ship shall have a nationality[.]").


                              - 83 -
documented");    

    § 12301   (providing    that    "[a]n   undocumented

vessel equipped with propulsion machinery of any kind shall have

a number issued by the proper issuing authority in the State in

which the vessel principally is operated"); see also U.K. Mar. &

Coastguard      Agency,     Guidance:       Vessel     Classification   and

Certification          (2018),     https://www.gov.uk/guidance/vessel-

classification-and-certification#certification-requirements-for-

uk-vessels (stating that, in the United Kingdom, a certificate of

registry is optional for "small commercial vessel[s]," defined as

vessels under 24 meters (roughly 79 feet)); R.R. Churchill & A.V.

Lowe, The Law of the Sea 213 n.19 (3d ed. 1999) (noting that "a

State may not require, or permit, the registration of ships below

a certain size"); Meyers, supra, at 160 ("Many states . . . do not

issue documents to ships with a tonnage below a given figure.").56


     56 We note that 24 meters (roughly 79 feet) is a cutoff point
for the applicability of several major international conventions.
See, e.g., International Convention on Tonnage Measurement of
Ships art. 4, June 23, 1969, 1291 U.N.T.S. 4 (exempting "ships of
less than 24 metres (79 feet) in length"); International Convention
on Load Lines art. 5, Apr. 5, 1966, 9159 U.N.T.S. 134 (same); see
also Gudrun Petursdottir, Olafur Hannibalsson & Jeremy M.M.
Turner, Part II: International Conventions and Guidelines on
Safety at Sea, in Safety at Sea as an Integral Part of Fisheries
Management, Food & Agric. Org. of the United Nations (2001),
available at https://www.fao.org/3/X9656E/X9656E01.htm (stating
that   recommendations    and   conventions    developed   by   the
International Maritime Organization and International Labor
Organization "are aimed at large vessels, primarily the merchant
fleet on international voyages" and observing that "[s]ome
conventions explicitly exempt fishing vessels, and most do not
apply to vessels under 24m thus leaving out the majority of fishing
vessels and transport boats in the developing countries").


                                   - 84 -
Hence, proof of a vessel's nationality via a centralized registry

or other evidence of registration may be unavailable, and a country

whose citizens have properly claimed nationality on behalf of their

vessels thus may be unable either to confirm or deny those claims

when contacted by the U.S. Coast Guard or other authorities.57

           Importantly, we do not suggest that international law

requires   the   United   States    to   accept   a   bare   assertion   of

nationality where there is conflicting evidence and attempts to

resolve the conflict prove fruitless.         Although the master's oral

declaration constitutes prima facie proof of nationality, that

verbal assertion can be undermined by contrary evidence, as is the

case for any prima facie showing.           For example, if the vessel's

claimed nationality differs from the nationality of most crew


According to the government, appellants' boat was 35 feet in
length. See supra note 4.
     57That may be what occurred in this case. The Department of
State's Certification, which describes the measures taken to
verify the master's claim of nationality, indicates that, on the
day the Coast Guard encountered the vessel -- October 29, 2015 --
U.S. officials "requested that the Government of the Republic of
Costa Rica confirm the registry or nationality of the suspect
vessel, and, if confirmed, provide disposition instructions."
Reyes-Valdivia, ECF No. 46-2, at 1 (Mar. 25, 2016) (emphasis
added). The Certification reports that, nearly three months later,
"the Government of Costa Rica replied that it could not confirm
[the] vessel's registry."    Id. (emphasis added).     Separately,
although not presented as an issue on appeal, the time lag between
the defendants' initial detention and Costa Rica's response to the
verification request strikes us as problematic, given that the
status of a vessel determines whether U.S. law enforcement
officials may proceed with prosecuting the crew members under the
MDLEA.


                                   - 85 -
members, or if a small vessel is interdicted far from the claimed

country,58 U.S. authorities could properly seek verification of the

master's claim.     In other words, where surrounding facts provide

legitimate   reason    to   doubt    an      oral   claim   of   nationality,

international law would permit the United States to treat the

vessel as stateless absent the sort of confirmation required by

§ 70502(d)(1)(C).     See, e.g., Commander's Handbook (2017), supra,

¶ 3.11.2.4 (stating that "[a] vessel may be assimilated to a vessel

without nationality" if, inter alia, there are contradictory or

inconsistent indicators of nationality).

          Put differently, when U.S. authorities are presented

with mixed signals about the nationality of a vessel, it would be

permissible under international law for the United States to seek

confirmation from the country of asserted nationality and, if none

is forthcoming, to treat the vessel as stateless.                 As we have

described, a vessel may be deemed stateless under international

law both when it "seeks to avoid national identification," Matos-

Luchi, 627 F.3d at 6, and when it "sails under the flags of two or


     58 The government posits such a scenario, asserting that it
would be absurd to require countries to accept unconfirmed verbal
claims of nationality because "[d]rug traffickers . . . could
falsely claim their vessels are the nationals of a small
Micronesian island or, more perplexingly, a country like North
Korea with limited diplomatic contacts." Appellee's Supp. Br. at
15.   We do not disagree.   Our analysis permits further inquiry
when a vessel's master claims a nationality that is at odds with
surrounding circumstances, including the vessel's location or the
nationality of the master and crew.


                                    - 86 -
more States," UNCLOS art. 92, § 2 -- two situations that produce

ambiguity concerning the vessel's nationality.59     International

law, by inference, likewise permits treating a vessel as stateless

when its master makes a verbal claim of nationality that is both

unsubstantiated and inconsistent with other relevant indicators of

the vessel's nationality.   As when the master of a vessel avoids

claiming a nationality or when a vessel indicates that it is

attempting to claim multiple nationalities, conflicting signals of

nationality create an ambiguity that properly gives rise to inquiry

and, absent confirmation, permits designation of the vessel as

"without nationality."60


     59  These two circumstances are reflected in the MDLEA's
provisions addressing vessels without nationality.      As we have
described, § 70502(d)(1)(B) covers the avoidance scenario,
defining a "vessel without nationality" to include one for which
the master fails "to make a claim of nationality or registry" upon
inquiry.    The scenario of multiple identities is covered in
§ 70502(c)(1)(B), which states that a "vessel subject to the
jurisdiction of the United States" includes "a vessel assimilated
to a vessel without nationality under paragraph (2) of article 6
of the 1958 Convention on the High Seas." Paragraph (2) of the
Convention states: "A ship which sails under the flags of two or
more States, using them according to convenience, may not claim
any of the nationalities in question with respect to any other
State, and may be assimilated to a ship without nationality." 1958
Convention on the High Seas, supra, art. 6.
     60 As described above, the government in its supplemental
briefing suggests that the circumstances here involved mixed
signals because, according to a Coast Guard officer's statement,
Reyes-Valdivia initially stated that the vessel lacked a
nationality.     Although the government noted the reported
disclaimer of nationality in its Motion in Limine in support of
jurisdiction, it chose for whatever reason not to include that
fact in the version of the facts presented at appellants' change-
of-plea hearing or in appellants' plea agreements.     See supra.


                              - 87 -
              However, that conflicting-signals limitation is not part

of § 70502(d)(1)(C) as currently enacted.           Rather, as we have

described, even where the circumstances offer no rationale for

displacing the prima facie showing of nationality established

through   a    verbal   claim,   § 70502(d)(1)(C)   treats    a   vessel   as

stateless based solely on the named country's failure to respond

"affirmatively and unequivocally" to U.S. inquiry.           The statute on

its face is thus inconsistent with international law,61 and we have

no license to rewrite it to satisfy constitutional requirements.

See Iancu v. Brunetti, 

 (2019) (stating that,

although the Court "may interpret 'ambiguous statutory language'


Accordingly, as     indicated in our discussion of the government's
Class argument,    see Section III supra, it may not rely now on that
untested fact.      Moreover, any attempt to raise a new theory of
prosecution at     this juncture would raise serious due process
questions.
     61 Although the government in its briefing at times depicts
appellants' claim that § 70502(d)(1)(C) is unconstitutional as an
as-applied challenge, that characterization is inapt.           The
classification of a vessel as stateless based solely on the named
country's indecisive response to inquiry, or its failure to
respond, is a "constitutional flaw evident in the statutory terms
themselves." Marc E. Isserles, Overcoming Overbreadth: Facial
Challenges and the Valid Rule Requirement, 48 Am. U.L. Rev. 359,
365 (1998); cf. Wash. State Grange v. Wash. State Republican Party,

 (2008) ("In determining whether a law is
facially invalid, we must be careful not to go beyond the statute's
facial requirements and speculate about 'hypothetical' or
'imaginary' cases.").    The mere fact that a cognizable legal
challenge by necessity concerns the application of a statute to
individuals does not transform a facial challenge into an as-
applied challenge.    See generally Richard H. Fallon, Jr., As-
Applied and Facial Challenges and Third-Party Standing, 

 (2000).


                                   - 88 -
to 'avoid serious constitutional doubts,' . . . '[w]e will not

rewrite a law to conform it to constitutional requirements'" (first

quoting FCC v. Fox Television Stations, Inc., 

(2009), and then quoting United States v. Stevens, 

 (2010))); see also Jennings v. Rodriguez, 

(2018) ("Spotting a constitutional issue does not give a court the

authority to rewrite a statute as it pleases.").                        It is up to

Congress to narrow the language of § 70502(d)(1)(C) if it so

chooses.62

             Even the absence of conflicting evidence of nationality,

however, does not mean that foreign nationals engaged in drug

trafficking on the high seas can evade prosecution based solely on

a   verbal   claim   --    whether    true    or    false    --    of    a    vessel's

nationality.    The Coast Guard and other countries' authorities can

always ask the claimed country of nationality for consent to arrest

and   prosecute      the    individuals       onboard.            See    

(c)(1)(C)      (stating       that    a     "vessel    subject         to   the

jurisdiction of the United States" includes "a vessel registered


      62We recognize that the three examples of vessels without
nationality listed in § 70502(d)(1) are not exclusive, and the
government might argue in future cases -- as the government
belatedly argued in this case -- that a vessel may be properly
deemed without nationality under the MDLEA based solely on mixed
signals, without the need to make any inquiry of the sort required
by § 70502(d)(1)(C). We need not, and therefore do not, consider
the viability of such an argument, including whether reliance on
a rationale for deeming a vessel without nationality that is not
expressly described in the MDLEA would raise due process concerns.


                                     - 89 -
in    a        foreign   nation    if    that   nation   has   consented     or   waived

objection to the enforcement of United States law by the United

States"); see also, e.g., Cardales-Luna, 

 (noting

that the United States obtained consent from the government of

Bolivia, which "waived objection to the enforcement of U.S. laws

by the United States with respect to the vessel . . . , including

its cargo and all persons onboard" (quoting State Department

certification));            Matos-Luchi,        627    F.3d    at    18   (Lipez,   J.,

dissenting) (noting that the government in that case had failed to

obtain consent from the likely country of nationality, "which could

have provided a fallback position in the event that the evidence

of statelessness proved deficient").

                  Indeed, it is common practice for countries, including

the       United     States,      to    negotiate     bilateral     and   multi-lateral

agreements to facilitate the apprehension of drug traffickers

operating on the high seas.                 See, e.g., Casavant, supra, at 205

(stating that the United States has entered into twenty-seven such

agreements, including with countries in South America, Central

America, and the Caribbean, providing a "process by which the two

[or more] nations can operate to suppress drug trafficking while

also respecting flag state jurisdiction").63                        The United States



       As previously noted, the United States relied on such an
          63

agreement to board appellants' vessel.   The State Department's
Certification reports that "United States law enforcement
personnel boarded the vessel" "pursuant to Article V of the


                                            - 90 -
also can address its concerns about maritime drug trafficking by

seeking to persuade other countries to take enforcement action

against their own vessels and nationals.                     See generally James

Kraska, Broken Taillight at Sea: The Peacetime International Law

of Visit, Board, Search, and Seizure, 

,

11   (2010)       ("Nowhere    is    collaboration         [among    countries]      so

ingrained than in counter-drug operations at sea.").                          In this

regard, a 2021 report by the U.S. Department of State noted that

the Coast Guard of Costa Rica -- the claimed flag-state here --

"is a successful regional partner with the United States for

maritime interdiction."         See U.S. Dep't of State, Bureau of Int'l

Narcotics     &    Law   Enforcement       Affairs,      Int'l    Narcotics   Control

Strategy Report, Vol. 1, Mar. 2021, at 117; see also 

("[A] bilateral agreement between the United States and Costa Rica

is regularly used in maritime drug interdiction operations[.]").

            What the United States cannot do consistently with the

Constitution,       however,    is   arrest        and   prosecute    foreigners      on

foreign vessels by relying on a concept of statelessness that

conflicts         with   international        law.          And     that   is       what

§ 70502(d)(1)(C)         allows.     It     overrides      international      law     by

treating a country's failure to supply an "affirmative[] and


Agreement between the Government of the United States of America
and the Government of the Republic of Costa Rica Concerning
Cooperation to Suppress Illicit Traffic." Reyes-Valdivia, ECF No.
46-2, at 1 (Mar. 25, 2016).


                                          - 91 -
unequivocal[]" confirmation of nationality -- including a failure

to respond at all -- as evidence sufficient to invalidate an oral

claim of foreign nationality even when there are no mixed signals

that would call the claim into doubt.             That is, the MDLEA treats

as stateless a vessel that, under international law, would be a

vessel with nationality.           Accordingly, the prosecution of foreign

nationals traveling on such a vessel for a violation of U.S. law

is impermissible under the Felonies Clause of the Constitution,

the only source of authority asserted for Congress's adoption of

the    MDLEA.       See    Aybar-Ulloa,   

   (referring           to

"Congress's power under Article I '[t]o define and punish Piracies

and Felonies committed on the high Seas'" (quoting U.S. Const.

art.   1,    § 8,   cl.10));       Mitchell-Hunter,      

    n.3

(explicitly stating that "[t]he MDLEA is derived from Congress'

power to 'define and punish Piracies and Felonies committed on the

high Seas'" (quoting U.S. Const. art. 1, § 8, cl.10)); Cruickshank,

 (same).

                                        VI.

             The    Framers    intended       international        law    to    be      a

constraint on Congress's authority "[t]o define and punish .                        .    .

Felonies committed on the high Seas."                 Two centuries ago, the

Supreme     Court   held    that    Congress    lacked    authority       under      the

Felonies Clause to extend U.S. jurisdiction to felonies committed

by foreign nationals on foreign vessels.              See Furlong, 18 U.S. (5


                                      - 92 -
Wheat.) at 198; Palmer, 

.                 With

§ 70502(d)(1)(C), Congress violated this principle, extending U.S.

jurisdiction beyond the limits of international law and, hence,

beyond the authority conferred by the Felonies Clause.

            In this case, relying on the authority provided by

§ 70502(d)(1)(C), the Coast Guard treated a vessel whose master

made    a   claim   of    Costa   Rican   nationality   cognizable   under

international law as a "vessel without nationality."           The United

States government improperly relied on that classification -- in

violation of constitutional limits -- to arrest and prosecute Costa

Rican citizens, Reyes-Valdivia and Dávila-Reyes.            We therefore

vacate their convictions and remand the case to the district court

with instructions to dismiss the MDLEA charges against them.64

            So ordered.




                         -CONCURRING OPINION FOLLOWS-




        Because we vacate appellants' convictions based on their
       64

Felonies Clause argument, we do not reach their due process
challenges to the MDLEA or Reyes-Valdivia's appeal from the
district court's application of the "captain" sentencing
enhancement.


                                   - 93 -
             HOWARD, Chief Judge, concurring in the result.        As noted

in the majority opinion, we withdrew our prior panel opinion and

granted panel rehearing after the en banc court issued its opinion

in Aybar-Ulloa.      In Aybar-Ulloa, the en banc court did not address

arguments raised by the parties about the protective principle.

In light of the now uncertain status of our protective principle

precedent, like my colleagues I am reluctant to unquestioningly

rely    on   the   protective   principle   to   affirm   the   convictions

underlying these appeals. Unlike my colleagues, I would not decide

these appeals on constitutional grounds.

             I would instead reverse these convictions on the basis

that the agreed facts do not support the statelessness claim

charged by the government.65       The government claims the vessel is

stateless per 

(d)(1)(C), which provides that

'vessels without nationality' include:


        Although this ground for reversal of the convictions was
       65

not initially raised in the appeals, the panel was concerned enough
about the mismatch that we requested that the parties brief the
issue, and they complied.    That the issue was addressed by the
parties through supplemental briefing may not by itself be reason
enough for us to bypass appellate waiver -- including not only the
failure to raise the issue on appeal but also, in the case of
Dávila-Reyes, the affirmative waiver of appeal contained in the
plea agreement.     But the majority's constitutional analysis
depends in part on an equivalency between "nationality" and
"registry" that it finds in § 70502(d)(1)(C).      My disagreement
about whether that equivalency exists is consequential, such that
it should not be relegated to a dicta detour along the way to
finding waiver. At this stage of the proceedings, the gap in the
statelessness determination under § 70502(d)(1)(C) is stark enough
for me to join the majority, albeit in result only.


                                   - 94 -
      a vessel aboard which the master or individual in charge
      makes a claim of registry and for which the claimed
      nation   of   registry  does   not   affirmatively   and
      unequivocally assert that the vessel is of its
      nationality.

The   majority    asserts       that   the   facts   here      meet   the   criteria

described   above    in     §    70502(d)(1)(C)      because     §    70502   treats

"registry" and "nationality" synonymously.                But I find no support

for that observation in the text of § 70502 or in our cases.

            To    reach         its    conclusion       that     "registry"      and

"nationality"     are     used    interchangeably        in    the    statute,   the

majority argues that interpreting these terms to have independent

meanings would leave an incongruous hole in statutory coverage;

how, the majority wonders, could Congress have intended to cover

a situation in which a master asserts Costa Rican registration,

but not Costa Rican nationality?

            The answer becomes apparent when we examine the overall

legal terrain.      Section 70502(d)(1) establishes three avenues to

find statelessness.       But this list is not exclusive, and leaves in

place other ways in which the government can establish lack of

nationality.     See United States v. Matos-Luchi, 

 (1st

Cir. 2010); 

 (Lipez, J., dissenting) ("As the majority

correctly holds, Congress did not intend those three examples [in

§ 70502(d)(1)] to be exhaustive.                The MDLEA extends to vessels

that are considered stateless under international law, even if

those   vessels     do not fall        within     one    of     the   specifically


                                       - 95 -
enumerated categories."); see also United States v. Miranda, 

 (D.C. Cir. 2015) ("[T]he statute contains three

nonexclusive examples of 'vessels without nationality,' each of

which turns on the 'registry' of the vessel."); United States v.

Rosero, 

 (3d Cir. 1994) (Alito, J.).         Thus, giving

meaning to all the terms in § 70502(d)(1) does not immunize vessel

masters who claim foreign nationality rather than registry.

            Here, the master asserted Costa Rican nationality for

the vessel; at no point did he assert Costa Rican registry.

Accordingly, by its terms, § 70502(d)(1)(C) is not applicable, nor

did   the   government   assert   an   alternative   basis   for   finding

statelessness when prosecuting appellants.           I would reverse the

convictions on that ground and go no further.




                                  - 96 -