For over a decade, family members of United States sailors killed in the bombing of the U.S.S. Cole have pursued litigation in federal court against the Republic of Sudan for its alleged support of A1 Qaeda, which was responsible for the bombing. This appeal arises. from the latest suit wherein the district court denied Sudan’s motion to. vacate the default judgments entered against , it. Because the Appellees’ method of serving process did not comport with the statutory requirements of 28 U.S.C. § 1608 (a)(3), we hold the district court, lacked personal jurisdiction over Sudan. Accordingly, we reverse the district court’s order denying Sudan’s motion to vacate, vacate the judgments, and remand with instructions.

I.

On October 12, 2000,' A1 Qaeda bombed the U.S.S. Cole, a United States Navy guided-missile destroyer, as it was refueling in the Port of Aden in Yemen. Seventeen American sailors were killed and forty-two more were injured.

A.

In 2004, family members of the deceased sailors filed a complaint against Sudan in the United States District Court for the Eastern District of Virginia (“the Rux litigation”). 1 Although foreign states generally enjoy immunity from suit in federal courts, 28 U.S.C. § 1604 , the Foreign Sovereign Immunity Act (“FSIA”) authorizes suits against a foreign state that has provided material support for certain acts of terrorism (“the terrorism exception”). Under the version of the FSIA in effect in 2004, the terrorism exception gave federal courts jurisdiction over the foreign state, but any claims had to be grounded in another substantive area of the law. See 28 U.S.C. §. 1605(a)(7) (repealed 2008). Accordingly, the Rux plaintiffs’ substantive claims rested on violations of the Death on the High Seas Act, .With .limiteid exceptions, Sudan did not enter appearances or otherwise defend the Rux suit. Following a series of rulings and appeals that are pot relevant to this appeal, the district court held that Sudan was liable and awarded compensatory damages to the plaintiffs. The Rux plaintiffs appealed the district court’s denial of their claim for additional damages. During the pendency of that appeal, Congress passed - the National Defense Authorization Act for- Fiscal Year *151 2008 (“NDAA”), Pub. L. No. 110-181, § 1083(b)(l)(A)(iii), 122 Stat. 341 .

The NDAA, which became effective on January 28, 2008, repealed the prior FSIA terrorism exception to foreign state immunity, reenacted the exception’s immunity-stripping language, and created a new substantive cause of action under the FSIA that authorizes recovery of noneconomic damages, including solatium and punitive damages. See NDAA, Pub. L. No. 110-181, § 1083 (codified at 28 U.S.C. § 1605A). The FSIA’s new cause of action also specifically authorizes suit based 'on certain pre-enactment events so long as delineated criteria are satisfied. § 1605A(b). We granted the Rux plaintiffs’ motion to remand for further proceedings in the district court in light of the revised statutory framework. Rux, 2009 WL 9057606 at *1.

On remand, the Rux plaintiffs sought leave to supplement their complaint to-include a claim for noneconoihic damages under § 1605A(c). The district court denied the motion and the Rux plaintiffs again appealed. While that appeal was pending, the Rux plaintiffs and four ;new plaintiffs filed “a new, related action pursuant to 28 U.S.C. § 1606A in the [United States District Court for the] Eastern District of Virginia.” Rux, 410 FedAppx. at 582. In relevant part, we held that the filing of this new complaint rendered moot the Rux plaintiffs’ arguments and we dismissed that appeal. Rux, 510 Fed.Appx. at 586.

B.

The current appeal arises from the district court’s adjudication of that “new, related action” brought under the amended FSIA. 2 Kumar filed the current complaint in April 2010, alleging that Sudan’s conduct satisfied the immunity-stripping language of § 1605A(a)(l) and caused the death of the seventeen sailors killed on board the U.S.S. Cole, in violation of the FSIA’s new cause of' action, § 1605A(c). He sought solatium and punitive damages.

'in an effort to effectuate service of pro: cess pursuant to 28'U.S.C. § 1608(a)(3), the clerk of court sent the requisite documents “via certified mail, return receipt requested,” in an enveloped addressed as follows;

REPUBLIC OF SUDAN Serve: Deng Alor Koul,

Minister of Foreign Affairs Embassy of the Republic of Sudan 2210 Massachusetts Avenue NW Washington, DC 20008

J.A. 158. Someone at the embassy accepted the envelope and signed the certified mail réceipt.

Nevertheless, Sudan did not enter an appearance or file any responsive pleadings. Consequently, Kumar moved for entry of default and for the court to schedule proceedings allowing adjudication of a default judgment. Following a bench trial, the district court “found that Sudan’s provision of material support and resources to al Qaeda led to the murders of the seventeen American servicemen and women *152 serving on the Cole, and entered judgment against Sudan under the FSIA.” J.A. 446. To more efficiently resolve the issue of damages, the court divided the suit into seventeen separate cases, each case involving all claims related to one of the seventeen deceased sailors.

• In March 2015, after considering additional evidence on the alleged damages, the district court entered separate default judgment orders collectively awarding over $20 million in solatium and approximately $14 million in punitive damages to the Kumar plaintiffs.

In April 2015, just over thirty days after entry of those orders, Sudan entered an appearance and moved to vacate the default judgments under Federal Rules of Civil Procedure 55(c) and 60(b). In the alternative, Sudan requested the district court extend its time to appeal from the default judgments. In support of its motion, Sudan asserted numerous arguments challenging the district court’s subject matter and personal jurisdiction, as well as the propriety of punitive damages.

The district court denied the motion to vacate, rejecting each of Sudan’s contentions. It did, however, grant Sudan’s motion for an extension of time to file a notice of appeal from thé March 2015 defaült judgments. Sudan' noted its appeal from both the default judgments and the denial of its post-judgment motions. In addition, Kumar noted a cross appeal challenging the district court’s order extending Sudan’s time to appeal. We have jurisdiction over both appeals pursuant to 28 U.S.C. § 1291 .

II.

Sudan contends the district court lacked personal jurisdiction over it. because Ku-mar did not properly effectuate service of process as required under the FSIA. Specifically, it contends that mailing service to the Sudanese embassy in Washington, D.C., does not satisfy 28 U.S.C. § 1608 (a)(3) and contravenes the 1961 Vienna Convention on Diplomatic Relations and Optional Protocol on Disputes (“Vienna Convention”), Apr. 18, 1961, 23 U.S.T. 3227, 500 U.Ñ.T.S. 95, which provides that a foreign state’s diplomatic mission is inviolable. If the district court lacked personal jurisdiction, then the judgment against Sudan is void. Koehler v. Dodwell, 152 F.3d 304 , 306-07 (4th Cir. 1998) (“[A]ny judgment entered against a defendant over whom the court does not have personal jurisdiction is void.”).

Because the issue before us is one of statutory interpretation, we review de novo the district court’s conclusion that Kumar’s method of serving process satisfied § 1608(a)(3). 3 Broughman v. Carver, 624 F.3d 670 , 674 (4th Cir. 2010).

A.

The Federal Rule of Civil Procedure governing service of process provides that “[a] foreign state ... must be served in accordance with 28 U.S.C. § 1608 ,” i.e., the *153 FSIA. Fed. R. Civ. P. 4(j)(l). That statute, in turn, describes four methods of serving process on a foreign state, listed in hierarchical order. § 1608(a).

The first method is “in accordance with any special arrangement for service between the plaintiff and the foreign state.” § 1608(a)(1). If no such arrangement exists, then service may be made “in accordance with an applicable international convention on service of judicial documents.” § 1608(a)(2). And “if service cannot be made under [either of these provisions, the specified documents,] together with a translation of each into the official language of the foreign state, [can be sent] by any form of mail requiring a signed receipt, to be addressed and dispatched by the clerk of the court to the head of the ministry of foreign affairs of the foreign state concerned.” § 1608(a)(3). Lastly,

if service cannot be made within 30 days under [the third method described, then two copies of the documents, along with the requisite translation can be sent] by any form of mail requiring a signed receipt, to be addressed and dispatched by the clerk of the court to the Secretary of State in Washington, District of Columbia, to the attention of the Director of Special Consular Services—and the Secretary ■ shall transmit one copy of thé papers through diplomatic channels to the foreign state and shall send to the clerk of the court a certified copy of the diplomatic note indicating when the papers were transmitted.

§ 1608(a)(4).

There is no dispute that the first two methods of service described in § 1608(a) were not available to Kumar. 4 Further, Kumar did not attempt to serve process by delivering the requisite documents through diplomatic channels as set out in subsection (a)(4), in part because failure of subsection (a)(3) service is a prerequisite to pursuing service under subsection (a)(4) and no question arose as to thé validity of Kumar’s'' method of serving process until after judgment.

The question before the Court, then, is limited to whether Kumar satisfied § 1608(a)(3), which allows service by mail “requiring a signed receipt! ] to be addressed and dispatched by the clerk of the court to the head of the ministry of foreign affairs of the foreign state.” Specifically, we must decide whether Kumar satisfied the “addressed and dispatched to” requirement when he submitted the packet to be mailed by the clerk of court to the Sudanese embassy in Washington, D.C. Sudan does not contest compliance with the other components of service under subsection (a)(3) and the- record shows Kumar instructed the clerk of court to send the requisite documents via the United States Postal Service’s certified mail system, which is “a[] form of mail requiring a signed, receipt.” Consequently, our review is limited to whether delivering process to a foreign nation’s embassy and identifying the head of that nation’s ministry of foreign affairs as the recipient satisfies subsection (a)(3)’s requirement that the mailing is “addressed and dispatched to the head of the ministry of foreign affairs of the foreign state.”

B.

As always, our duty in a case involving statutory interpretation is “to ascertain and implement the intent of Con *154 gress.” Broughman, 624 F.3d at 674 . 5 We begin with the statute’s text. Ross v. R.A. North Dev., Inc. {In re. Total Realty Mgmt. LLC), 706 F.3d 246 , 254 (4th Cir. 2013). In addition, “[t]he Supreme Court has. often emphasized the. crucial role of context as a tool of statutory construction. For example, the Court has stated that when construing a statute, courts must not be guided by a single sentence or member of a sentence, but look to the provisions of the whole law, and to its object and policy.” Br own & Williamson Tobacco Corp. v. FDA, 153 F.3d 155 , 162 (4th Cir. 1998). As a result, “the traditional rules of statutory construction to be used in ascertaining congressional intent include: the-overall statutory Scheme, legislative history, the history of evolving congressional regulation in the area, and a consideration of other relevant statutes.” Id.

We begin with’a general observatióh: based on § 1608(a)’s four precise methods for service of process and how that language contrasts with § 1608(b), subsection (a) requires strict compliance. Subsection (b), which applies in suits against “an agency or instrumentality of a foreign state,” contains both specific methods of serving process, § 1608(b)(l)-(2), and a catchall provision expressly allowing service by any method “reasonably calculated to give actual notice,” § 1608(b)(3). Although Congress authorized an array of specific and general service options under subsection (b), it did not include a similar catchall provision in subsection ■ (a). This contrast between two subsections of the same statute suggests that Congress intended that, the four methods authorized under subsection.(a).be the exclusive and explicit means of effectuating service of process against foreign states. Russello v. United States, 464 U.S. 16 , 23, 104 S.Ct. 296 , 78 L.Ed.2d 17 (1983) (‘Where' Congress includes particular language in one section of a statute but omits it in another section of the same Act, it is generally presumed, that Congress acts intentionally and purposely in the disparate inclusion or exclusion.”). In other words, had Congress intended for a non-delineated method or actual. notice to satisfy the requirements for serving process on a foreign state, it would have indicated as much by including a similar “reasonably calculated” provision in subsection (a). It did not do so.

Thus, a court cannot excuse noncompliance with the specific requirements of § 1608(a). See Magness v. Russ. Federation, 247 F.3d 609 , 612-617 (5th Cir. 2001) (“Based on [other decisions], the express language of section 1608(a), and the United States’ interest in ensuring that the proper officials of a foreign state are notified when a suit is instituted, we hold that plaintiffs must strictly comply with the statutory service of process provisions when suing a foreign state ... under-section 1608(a).”); Transaero, Inc., v. La Fuerza Aerea Boliviana,. 30, F.3d ■ 148, 153-54 (D.C. Cir. 1994) (“We hold that strict adherence to the terms of 1608(a) is required.”). 6 In short, “[ljeniency” when applying § 1608(a). “would disorder the statutory scheme” Congress enacted. Transaero, 30 F.3d at 154.

*155 We now turn to what, specifically, subsection (a)(3) requires of a plaintiff. First, we note the text does not specify a geographic location for the service of process. Instead, subsection (a)(3). requires that the mailing of process be “addressed and dispatched” to the head of the ministry of foreign affairs. This phrase does not meaningfully limit the geographic location where service is to be made, though it.does reinforce that the location must be related to the intended recipient. See address, Oxford English Dictionary (defining the verb “address” as “[t]o send in a particular direction , or towards a particular location” or “(t]o direct (a written communication) to a specific person or destination,” “[t]o direct to the attention of, communicate to”); dispatch, Oxford English Dictionary (defining the verb “dispatch” as “[t]o send off post-haste or with expedition or promptitude (a messenger, message, etc., having an express destination). The word regularly used for the sending of official messengers, and messages, of couriers, troops, mails, telegrams, parcels, express trains, packet-boats, etc,”). As we discuss below, our sister circuits have held that subsection (a)(3) is satisfied where process is mailed to the head of the ministry of foreign affairs at the ministry of foreign affairs’ address in the foreign state. See, e.g., Gates v. Syrian Arab Republic, 646 F.3d 1 , 4-5 (D.C. Cir. 2011); Peterson, 627 F.3d at 1129. But Kumar contends that subsection (a)(3)’s silence as to geographic location for the mailing means that the statute does not require service to be sent to the foreign state and that it allows service delivered to the foreign state’s embassy in the United States.

Although Kumar does not advocate such an extreme position, the view that subsection (a)(3) only requires a particular recipient, and not a particular location, would allow the clerk of court to send service to any geographic location so long as the head of the ministry of foreign affairs of the defendant foreign state is identified as the intended recipient. That view cannot be consistent, with Congress’ intent: otherwise, service via General Delivery in Peoria, Illinois could be argued as sufficient.

, While it is true that subsection (a)(3) does not specify delivery only at the foreign ministry in the foreign state’s capital, Kumar’s premise that subsection (a)(3) does not require service to be sent there does not lead to his conclusion that service at the embassy satisfies the obligation under subsection (a)(3). The statute is simply ambiguous as to whether delivery at the foreign state’s embassy meets subsection (a)(3) given that while the head of a ministry of foreign affairs generally oversees a foreign state’s embassies, the foreign minister is rarely—if ever—present there. Serving the foreign- minister at a location removed from where he or she actually works is at least in tension with Congress’ objective, even if it is not strictly prohibited by the statutory language.

Because the plain language of subsection (a)(3) does not- fully resolve the issue before us, we turn elsewhere for guidance as to Congress’ intent. See Lee v, Norfolk S. Ry. Co., 802 F.3d 626 , 631 (4th Cir. 2015) (“[I]f the text of a statute is ambiguous, we look to other indicia of congressional intent such as the legislative history to interpret the statute.”). Here, the FSIA’s legislative history, coupled with the United States’ obligations under the Vienna Convention, as well as the “great weight” aceorded the State Department’s interpretation of such .foreign treaty matters, lead us to the conclusion that subsection (a)(3) is not satisfied by delivery of process to a foreign state’s embassy.

To understand this interplay, we first observe the obligation under the Vienna Convention that “[t]he premises of the *156 mission shall be inviolable. The agents of the receiving' State may not enter them, except with the consent of the head of the mission.” 7 Vienna Convention, supra art. 22, ¶ 1. Elsewhere, the Vienna Convention protects the inviolability of diplomatic agents. See id. art. 29. 8

The House Judiciary Committee Report regarding the enactment of § 1608(a) shows that the statute is meant to account for the United States’ rights and obligations under the.Vienna Convention. See H.R, Rep. No. 94-1487 (1977), as reprinted in 1976 U.S.C.C.A.N. 6604. The FSIA— including § 1608 in its present form—was first enacted in 1976, four years after the Vienna Convention entered into force for the United States. See Tabion v. Mufti, 73 F.3d 535 , 538 n.5 (4th Cir. 1996). Congress knew and considered the Convention’s obligations in drafting the FSIA. Specifically, the first draft of the bill allowed for service on a foreign state by “registered or certified mail ... to the ambassador or chief of mission of the foreign state.” S. 566, 93d Cong. § 1608 (2d Sess. 1973). The Department of State recommended removing that option based on its view that this method of service would violate Article 22 of the Vienna Convention. See H.R. Rep. No. 94-1487, at 26, as reprinted in 1976 U.S.C.C.A:N., at 6625; 71 Dep’t of State Bull. 458, 458-59 (1974).

The House Report also took ’“[sjpecial note” of a “means ... currently in use in attempting to commence litigation against a foreign state.” H.R. Rep. No. 94-1487, at 26, as reprinted in 1976 U.S.C.C.A.N., at 6625. Describing “the mailing of a copy of the summons and complaint to a diplomatic mission of the foreign state” as a means of serving process that was “of questionable validity,” the House Report states that “[sjection 1608 precludes this method [of service] so as to avoid questions of inconsistency with section 1 of article 22 of the Vienna Convention on Diplomatic Relations^]” Id. (emphases added). The Report then reiterates “[sjervice on an embassy by mail would be precluded under this bill.” Id. (emphasis added). Thus, the House Report confirms that Congress did not intend § 1608 to allow for the mailing of service “to” or “on” a diplomatic mission as such a method would transgress the treaty obligations of the United States under the Vienna Convention.'

In previously interpreting other provisions of the Vienna Convention, we have recognized that it “should be construed to give effect to the intent of the signatories,” considering both its language and “the context in which the words were used.” Tabion, 73 F.3d at 537 . Moreover, “[tjreaties generally are liberally construed.” .Id. The question then becomes whether the Vienna Convention’s inviolability provision prohibits the application of subsection (a)(3) in the manner that allows service of process as Kumar executed in this case: service delivered to the foreign nation’s embassy-in the United States. We conclude the Vienna Convention does exactly that.

*157 Kumar contends there is a dispositive difference for purposes of subsection (a)(3) when an embassy itself is served at the embassy’s address (which Kumar agrees would violate the Vienna Convention) and when the head of the ministry of foreign affairs is served at the embassy’s address (which Kumar contends does not violate the Vienna Convention). We fail to discern any meaningful distinction here. In the first instance, both the embassy and its address are used in an attempt to serve the foreign state; in the second, the embassy address is used as the head of the ministry of foreign affairs’ address in an attempt to serve the foreign state. In both cases, a plaintiff has relied on the foreign states’ embassy as the vehicle for effectuating service of process on the foreign state. Either action impinges upon the unique characteristics of a diplomatic mission recognized and protected by the Vienna Convention and casts the embassy in the role as agent for service of process. Any distinction between service “on” the embassy or “via” the embassy thus seems a meaningless semantic distinction. 9

In foreign affairs matters such as we consider here, we afford the view of the Department of State “substantial deference.” See Abbott v. Abbott, 560 U.S. 1 , 130 S.Ct. 1983 , 1993, 176 L.Ed.2d 789 (2010) (“It is well settled that the Executive Branch’s interpretation of a treaty is entitled to great weight.”); Tabion, 73 F.3d at 538 (“Substantial deference is due to the State Department’s conclusion” about the meaning of a treaty’s provisions). This judicial deference stems in part from the Constitution’s grant to the Executive Branch—not the Judicial Branch—of broad oversight over foreign affairs. Compare U.S. Const, art. 2, § 2, cl. 2, and § 3 (reserving to the Executive Branch the ability to “make Treaties” and “receive Ambassadors and other public Ministers”), with U.S. Const, art. 3 (containing no similar oversight of foreign affairs). In this case, the State Department contends that service at an embassy does not satisfy subsection (a)(3) and is inconsistent with the United States’ obligations under the Vienna Convention. See Br. for the United States as Amicqs Curiae in Supp. of Reversal 11 (“There is an international consensus that a litigant’s service of process through mail or personal delivery to a foreign mission is inconsistent with the inviolability of the mission enshrined in” Article 22 of the Vienna Convention).

Relatedly, the Court properly considers the diplomatic interests of the United States when construing the Vienna Convention and the FSIA. See Persinger v. Islamic Republic of Iran, 729 F.2d 835 , 841 (D.C. Cir. 1984) (noting that, in construing the FSIA, courts should consider the United States’ interest in reciprocal treatment abroad). The United States has represented that it routinely “refuses to recognize the propriety of a private party’s service through mail or personal delivery to a United States embassy.” Br. for the United States as Amicus Curiae in Supp. of Reversal 13. The following example illustrates the wisdom of deferring to the *158 State Department’s interpretation in this area: As noted, citing the Vienna Convention’s provisions, the Secretary of State “routinely refuses to recognize” attempts to serve process on the United States by mail sent to U.S. embassies in foreign states. See Br. for the United States,as Amicus Curiae in Supp. of Reversal 13-14. The legitimacy and sustainability of that position would be compromised were we to countenance Kumar’s method of serving process to the Sudanese embassy. Why would a foreign judiciary recognize the United States’ interpretation of the Vienna Convention when it comes to rejecting service of process via its own embassies if that same method for purposes of serving process on foreign states were permitted in the United States? Clearly, the United States cannot expect to receive treatment under the Vienna--Convention that its own courts do not recognize in similar circumstances involving foreign states. This dilemma is avoided by the construction of subsection (a)(3) urged by the State Department. We find its longstanding policy and interpretation of these provisions authoritative, reasoned, and entitled to great weight.

In view of the ambiguity in § 1608(a)(3) as to the place of service, we conclude the legislative history, the Vienna Convention, and the State Department’s considered view to mean that the statute does not authorize delivery of service to a foreign state’s embassy even if it correctly identifies the intended recipient as the head of the ministry of foreign affairs. Put another way, process is not properly “addressed and" dispatched to” the head of the ministry of foreign affairs as required under § 1608(a)(3) when it is delivered to the foréign state’s embassy in Washington, D.C'.

We recognize that this holding adds to the existing tension between the courts of appeals’ interpretations of § 1608(a)(3), but it. aligns with the greater weight of those holdings. For instance, it is consistent with the approaches taken in the D.C. and Seventh Circuits. Although it has not been confronted with the precise issue raised in this case, the D.C. Circuit has suggested that § 1608(a)(3) requires service on the. head of the ministry of foreign affairs in the foreign state. See Barot v. Embassy of the Republic of Zam., 785 F.3d 26 , 28, 30 (D.C. Cir. 2015) (noting that the district court rejected plaintiffs attempt to serve process at the Zambian Embassy “in Washington D.C., rather than at the Ministry of Foreign Affairs in Lusaka, Zambia, as the Act required” and remanding to the district court so the plaintiff had the opportunity “to effect service pursuant to [28 U.S.C. § ] 1608(a)(3)” by having the clerk of - court send service “to the head of the . ministry of foreign affairs in Lusaka, Zambia, whether identified by name or title, and not to any other official or agency”), Similarly, the.Seventh Circuit observed that the Vienna Convention and § 1608 both prohibited a plaintiff from effectuating service under subsection (b)(3)’s catchall provision by serving process on a foreign company “wholly owned by the Belarusian government” by delivering it to the Belarusian ambassador at the embassy in Washington, "D.C. Autótech Techs. LP v. Integral Research'& Dev. Corp., 499 F.3d 737 , 739, 749-50 (7th Cir. 2007)' (holding “service through an embassy is expressly banned both by an international treaty to which the United States is a party and by U.S. statutory law” because the treaty prohibits service on a diplomatic officer and § 1608 does not authorize service of process on an ambassador (emphasis added)). 10

*159 Our holding conflicts with the view of the Second. Circuit, which has held that serving Sudan’s head of the ministry of foreign affairs in a package that was delivered by certified mail to the Sudanese embassy in Washington, D.C., satisfies § 1608(a)(3). Harrison v. Republic of Sudan (Harrison I), 802 F.3d 399 , 402-06 (2d Cir. 2015), reh’g denied, 838 F.3d 86 (Harrison II) (2d Cir, 2016) (denying petition for rehearing following further briefing and argument, and elaborating on the reasons for affirmance). The Second Circuit concluded “principles of mission inviolability and diplomatic immunity are [not] implicated” where service is made “via the embassy address.” Harrison I, 802 F.3d at 405 ; see also Harrison II, 838 F.3d at 94 (distinguishing between service “on the Minister of Foreign Affairs at the foreign mission” and service “on the foreign mission itself or the ambassador”). For the reasons we’ve already explained, we And the Second Circuit’s reasoning weak and unconvincing. 11 , 12

Several additional grounds the Second Circuit relied on merit brief discussion as well. ■ First, after acknowledging § 1608(a)(3)’s silence as to geographic location* the- court noted that “[i]f Congress had wanted to require that the mailing be sent to the head of the ministry of foreign affairs in the foreign country, it could have said so. In § 1608(a)(4), for example, Congress specified that the papers be mailed to the Secretary of State in Washington, District of Columbia[.]” Harrison I, 802 F.3d at 404 ; accord Harrison II, 838 F.3d at 91 (“If Congress had wanted to require that the mailing be sent to the minister of foreign affairs at the principal office of the ministry in the foreign country,-it could have said so—but it did not.”). We do not find this point to be persuasive given that subsection (a)(4) directs attention to one known location for one country—the United States—and so can be easily identified. See 28 U.S.C. § 1608 (a)(4).

Second, the Second Circuit observed that requiring process “to a ministry of foreign . affairs in the foreign country, *160 makes little sense from a reliability perspective and as a matter of policy” given the reliability of a diplomatic pouch. Harrison I, 802 F.3d at 406 ; accord Harrison II, 838 F.3d at 90 & n.3 (approving of service on an embassy because such service “could reasonably be expected to result in delivery to the intended person,” as the embassy “is the nerve center for a country’s diplomatic affairs within the borders of another nation”). This misses the mark for multiple reasons. Reliability and policy concerns have no role when considering what the text of the statute—construed in light of the Vienna Convention— means. Subsection (a)(3) requires plaintiffs to attempt service by mail “requiring a signed receipt,” but leaves the specific use of certified mail or other method open to take into account concerns about reliability of service on a particular foreign state. Moreover, § 1608(a) specifically contemplates that service via subsection (a)(3) may not be possible in every foreign state, as recognized by subsection (a)(4), which allows for service under the alternative of using diplomatic channels. If, after thirty days, a plaintiff is unable to effectuate service pursuant to subsection (a)(3), he or she can turn to subsection (a)(4). That is the subsection that Congress intended plaintiffs to use to take advantage of the reliability and security of the diplomatic pouch.

Further, the method to effectuate service of process the United States undertakes does not violate the Vienna Convention because it respects international norms of communication via diplomatic channels. See Oct. 26, 2017, Letter from the United States as Amicus Curiae 1-2 (“When transmitting legal process through diplomatic channels, the State Department’s typical practice is for the United States’ embassy in the foreign state to deliver the papers to the state’s foreign ministry. In some unusual circumstances, or if the foreign state so requests, the State Department will transmit process to a foreign state’s embassy in the United States. In either case, the- State Department transmits the papers under cover of a diplomatic note to the foreign state. ... [T]his transmission of legal papers from one executive to another is considered to be communication through diplomatic channels.” (emphasis added)). Certified mail sent from the clerk of court to the head of the ministry of foreign affairs at the foreign state’s embassy is not of the same level and protocol and does not similarly respect the inviolability of the embassy for purposes of complying with the Vienna Convention.

III.

Because the attempted service of process in this case did not comply with the FSIA’s statutory requirements, the district court lacked personal jurisdiction over Sudan and could not enter judgment against it. See 28 U.S.C. § 1330 (b) (“Personal jurisdiction over a foreign state shall exist as to every claim for relief over which the district courts have jurisdiction ... where service has been made under [ 28 U.S.C. § 1608 (a)].”); see also Ruhrgas AG v. Marathon Oil Co., 526 U.S. 574 , 584, 119 S.Ct. 1563 , 143 L.Ed.2d 760 (1999) (“Personal jurisdiction ... is an essential element of the jurisdiction of a district court, without which the court is powerless to proceed to an adjudication.”). For that reason, the judgments entered against Sudan are void.

We therefore reverse the district court’s denial of Sudan’s motion to vacate the entry of judgment, vacate the judgments against it, and remand to the district court with instructions to allow Kumar the opportunity to perfect service of process in a manner consistent with this opinion.

*161 REVERSED IN PART, VACATED IN PART, AND REMANDED WITH INSTRUCTIONS