Full opinion text
Dissenting opinion filed by Circuit Judge Henderson. Srinivasan, Circuit Judge: This case involves a United States citizen who has been detained by the United States military in Iraq for several months. He seeks release from military custody in a habeas corpus action brought under the pseudonym John Doe. Doe is a citizen not only of the United States but also of Saudi Arabia. Doe was initially captured in Syrian territory controlled by the Islamic State of Iraq and the Levant (ISIL). The Department of Defense determined that he is an enemy combatant for ISIL, and the Department has been detaining him at a military facility in Iraq. Doe's habeas petition contends that he must be released because, he claims, ISIL combatants do not come within any existing authorization for use of military force. He also contends that he is not in fact an ISIL combatant. At this stage of the proceedings, no court has addressed the merits of those claims. This appeal instead concerns a separate claim by Doe: that the government, while his habeas petition remains pending, cannot forcibly-and irrevocably-transfer him to the custody of another country. Transfer of Doe to another country's custody would, naturally, obviate any occasion to seek release from physical custody at the hands of the United States. In connection with the possibility of Doe's forcible transfer to the custody of another country, the district court has entered two orders we now review. In the first order, the court required the government to give 72 hours' notice before transferring Doe to the custody of any other country. The notice period was meant to afford the court an opportunity to review the circumstances of a planned transfer before it takes place. The government seeks to set aside any obligation to give advance notice with regard to two specific countries. We will refer to those countries as Country A and Country B because of the government's desire to withhold public release of their identities due to apparent sensitivities associated with ongoing or future diplomatic discussions. The district court's second order came about after the government reached an agreement with Country B to transfer Doe to its custody. The government gave the district court the requisite notice of its intent to transfer Doe to that country. The court then enjoined the government from effecting the transfer. In the court's view, the government had failed to demonstrate the necessary legal authority (specifically, a statute or treaty) for the transfer. We sustain both of the district court's orders. In claiming the authority to forcibly transfer an American citizen held abroad to the custody of another country, the government ultimately relies on two species of argument. Neither, in our view, gives the government the power to effect its desired handover of Doe to Country B, at least as things currently stand. The first rationale advanced by the government has no necessary grounding in Doe's designation as an enemy combatant or in the military's authority under the law of war. Rather, the government relies on Supreme Court decisions recognizing that, when a foreign country wants to prosecute an American citizen already present in its territory for a crime committed within its borders, the Executive can relinquish her to that country's custody for purposes of criminal proceedings. See Munaf v. Geren , 553 U.S. 674, 128 S.Ct. 2207, 171 L.Ed.2d 1 (2008) ; Wilson v. Girard , 354 U.S. 524, 77 S.Ct. 1409, 1 L.Ed.2d 1544 (1957). Those decisions, on the government's reading, extend past their facts in two ways: (i) they enable a forcible transfer of a U.S. citizen to a different foreign country than the one in which she is already present, and (ii) they enable a forcible transfer as long as the receiving country has some legitimate sovereign interest in her (whether or not related to criminal prosecution). No. 18-5032, Gov't Opening Br. 23-25. We cannot accept the government's argument. We know of no instance-in the history of the United States-in which the government has taken an American citizen found in one foreign country and forcibly transferred her to the custody of another foreign country. Under the logic of the government's position, it could pick up an American traveling in Europe and involuntarily relinquish her to, say, the custody of Afghanistan, as long as Afghanistan is thought to have some cognizable sovereign interest in her. We cannot conclude that the government possesses that kind of authority over a U.S. citizen, at least without a statute or treaty specifically providing for it. The government's second line of argument differs from its first in an important respect: the second argument turns on Doe's status as an alleged enemy combatant and on the military's attendant authority in a time of war. We agree with the government that, if Doe is an enemy combatant, the military can transfer him to the custody of Country B, a partner in the campaign against ISIL. But under the precedents of the Supreme Court and our court, two conditions must exist for an American citizen to be subject to military transfer or detention as an enemy combatant: (i) there must be legal authority for the Executive to wage war against the enemy, and (ii) there must be an opportunity for the citizen to contest the factual determination that he is an enemy combatant fighting on behalf of that enemy. See Hamdi v. Rumsfeld , 542 U.S. 507, 517, 533, 124 S.Ct. 2633, 159 L.Ed.2d 578 (2004) (plurality opinion); Omar v. McHugh , 646 F.3d 13, 24 (D.C. Cir. 2011). Neither the legal inquiry nor the factual inquiry has taken place in this case. In the absence of those inquiries, we see no basis to set aside the district court's injunction barring the forcible transfer of Doe to Country B. What about the district court's order requiring the government to give 72 hours' notice before transferring Doe to either Country A or Country B? Because the government gave notice of the proposed transfer to Country B, the government's appeal of the notice order as it applies to Country B is now moot. With regard to Country A, the government has yet to come forward with any information about the circumstances of a prospective transfer to that country, including the specific purpose or interest that will give rise to the transfer. The government instead seeks ex-ante, carte-blanche authorization to transfer Doe to Country A, regardless of the particular circumstances or reasons, and without any opportunity for judicial review. We conclude that the district court did not err in denying the government that sort of blanket preapproval. While we sustain the district court's orders, we do so respectful of-and with appreciation for-the considerable deference owed to the Executive's judgments in the prosecution of a war. That latitude of course extends to military decisions about what to do with enemy combatants captured overseas in a zone of active hostilities. Virtually all such decisions will be unaffected by our decision today. But when an alleged enemy combatant-even one seized on a foreign battlefield-is an American citizen, things are different. See Hamdi , 542 U.S. at 532-33, 535-37, 124 S.Ct. 2633 (plurality); id. at 558-59, 124 S.Ct. 2633 (Scalia, J., dissenting). In that "surely ... rare" circumstance, id. at 571, 124 S.Ct. 2633 n.3 (Scalia, J., dissenting), the Executive's authority to wage war as it sees fit is cabined by the Supreme Court's decision in Hamdi , which requires that a citizen be afforded certain guarantees before the military detains or transfers him under the law of war. Id. at 517, 533, 124 S.Ct. 2633 (plurality); Omar , 646 F.3d at 24. That precedent, in our view, governs the disposition of this appeal. I. A. In September 2017, Syrian Democratic Forces encountered Doe at a screening point on an active battlefield in Syrian territory controlled by ISIL. Doe surrendered, informed the Syrian Democratic Forces that he was an American citizen, and asked to speak to U.S. officials. The Syrian Democratic Forces transferred Doe to the custody of U.S. military forces in the region. The military reached a preliminary determination that Doe is an enemy combatant, and has detained him at a U.S. facility in Iraq for the past seven months. The military's preliminary determination that Doe is an enemy combatant is based on evidence that he is a member or substantial supporter of ISIL. The evidence against Doe includes the following: the circumstances of his surrender, his statements upon surrender and during detention, and records of his ISIL membership. ISIL, also known as the Islamic State of Iraq and Syria (ISIS), has been designated as a terrorist group. It controls territory in Iraq and Syria, and has perpetrated and aided terrorism there and around the world, killing several thousand civilians, including American aid workers and journalists. See U.S. Dep't of State, Bureau of Counterterrorism, Country Reports on Terrorism 2016: Chapter 6, Terrorist Organizations (July 2017). Since September 2014, the United States has pursued a counterterrorism strategy against ISIL, and is an active member of a 75-country coalition working to defeat ISIL in Iraq and Syria. B. In October 2017, the American Civil Liberties Union Foundation, acting on Doe's behalf, petitioned the district court for a writ of habeas corpus. The petition asserts that the military's existing authority to engage in armed conflict does not extend to ISIL, that the military thus lacks legal authority to detain an alleged member of ISIL, and that, as a result, the government must either prosecute Doe in an Article III court or release him. In addition to those legal arguments, Doe contends as a factual matter that he is not an ISIL combatant. The district court determined that the ACLU had standing to bring the action on Doe's behalf. The court ordered the government to give the ACLU access to Doe to ascertain whether he wanted to continue the action. Am. Civil Liberties Union Found. v. Mattis , 286 F.Supp.3d 53, 60-61 (D.D.C. Dec. 23, 2017). On January 5, 2018, the ACLU informed the court that Doe wanted to continue pursuing the habeas petition with the ACLU representing him. The ACLU then asked for an order barring the government from transferring Doe to another country until the court decided the merits of his petition. On January 23, the district court granted Doe's request in part. The court entered a preliminary injunction requiring the government to provide 72 hours' notice before transferring Doe to any other country. The court determined that Doe had proven a likelihood of success because the government had failed to demonstrate that it had the requisite legal authority to transfer him to another country. The court further concluded that Doe had shown irreparable injury, reasoning that transfer out of U.S. custody would render him "unable to pursue his habeas petition." Doe v. Mattis , 288 F.Supp.3d 195, 200 (D.D.C. 2018). Finally, the court weighed the government's interest in maintaining productive diplomatic relations with potential transferee countries against a U.S. citizen's right to contest the lawfulness of his detention, concluding that both the balance of equities and the public interest favored Doe. Finding the requirements for a preliminary injunction to have been met, the court entered its order requiring 72 hours' notice so that Doe would have an opportunity to challenge a proposed transfer before it happened. The government appealed. It initially asked this court to vacate the preliminary injunction so that it could transfer Doe to any country without providing advance notice. No. 18-5032, Gov't Opening Br. 27-28. In the alternative, the government asked for vacatur of the notice requirement as applied to one specified country "or any other country that the Executive Branch determines has a legitimate interest in petitioner." Id. at 38. Later, in its reply brief, the government narrowed the scope of its appeal still further, such that it now seeks vacatur of the notice requirement only as applied to Countries A or B. No. 18-5032, Gov't Reply Br. 2 n.1. On April 16, 2018, while the government's appeal of the notice injunction was pending, the government filed a notice in the district court in compliance with that injunction. The notice communicated the government's intent to transfer Doe to the custody of Country B in 72 hours. Attached to the notice was a sworn declaration from a Deputy Assistant Secretary of State, who averred that Country B had expressed a "strong interest" in taking custody of Doe and continuing to detain him in some form. Doe v. Mattis , No. 17-cv-2069, Notice attach. 1 at 4-5 (D.D.C. Apr. 17, 2018), ECF No. 80. Doe moved for a preliminary injunction or temporary restraining order to block the proposed transfer. On April 19, 2018, the district court granted the preliminary injunction, barring the government "from transferring [Doe] from U.S. custody." Doe v. Mattis , No. 17-cv-2069, Prelim. Inj. (D.D.C. Apr. 19, 2018), ECF No. 88. While the order could be read to bar transfer to any foreign country, we understand it to grant only the relief Doe requested (and thus only the relief the government had notice might be imposed)-that is, a bar on transfer to Country B specifically. Cf. Capital City Gas Co. v. Phillips Petrol. Co. , 373 F.2d 128, 131 (2d Cir. 1967). In support of the order, the court again concluded that Doe had demonstrated a likelihood of success on the merits because the government had failed to identify the requisite legal authority for a forcible transfer of Doe to Country B. And for the same reasons it gave when it entered the notice injunction, the court concluded that Doe would be irreparably injured absent an injunction and that the balance of equities and public interest weighed in his favor. The government appealed the second injunction to this court. It then moved for consolidation of the two appeals and expedited treatment, both of which we granted. This opinion thus resolves both of the government's appeals. In view of the presumption of public access to judicial proceedings, we have endeavored to fashion the opinion so as to manage redactions while still not revealing the identities of Countries A and B. II. The government appeals two orders granting injunctive relief to Doe: the order requiring the government to give 72 hours' notice before transferring Doe to Country A or B (the only countries as to which the government appeals the notice obligation); and the order prohibiting the government from transferring Doe to Country B. While both orders are denominated preliminary injunctions, the latter appears to function as a permanent injunction. A district court facing a request for a preliminary injunction must balance four factors: (i) whether the party seeking the injunction is likely to succeed on the merits of the action, (ii) whether the party is likely to suffer irreparable harm without an injunction, (iii) whether the balance of equities tips in the party's favor, and (iv) whether an injunction would serve the public interest. Winter v. Nat. Res. Def. Council, Inc. , 555 U.S. 7, 20, 129 S.Ct. 365, 172 L.Ed.2d 249 (2008). The same factors apply when a party seeks a permanent injunction, except the party must show "actual success" on the merits rather than just a likelihood. Id. at 32, 129 S.Ct. 365. We review the district court's balancing of those considerations for an abuse of discretion, but review any underlying legal conclusions de novo. Abdullah v. Obama , 753 F.3d 193, 197-98 (D.C. Cir. 2014). A. We first consider the order enjoining the Secretary from transferring Doe to Country B. We address each of the injunction factors in order. 1. In assessing whether Doe has succeeded on the merits, the relevant question is whether, in the circumstances of this case, involuntarily transferring Doe to Country B would be unlawful. We hold that it would be. The government makes two species of arguments as to why the Executive has the power to transfer Doe to Country B without his consent. The first rationale has no necessary connection to Doe's designation as an enemy combatant, or even to the wartime context of this case. It instead relies on a general understanding that, when a foreign country wants to prosecute an American citizen already in its territory for a crime committed within its borders, the Executive can relinquish him to that country's custody for criminal proceedings. The government's second rationale, unlike the first, hinges on Doe's status as an enemy combatant. That second strand of the argument relies on the military's asserted authority under the law of war to transfer an enemy combatant (including an American citizen) to an allied country in the conflict. Neither of the government's rationales, we conclude, supports the involuntary transfer of Doe to Country B, at least as things currently stand. In reaching that conclusion, we rely on the same undisputed facts as our dissenting colleague: that Doe is an American citizen, that he is in U.S. custody in Iraq, that the government believes he is an ISIL combatant, and that he objects to the government's forcible transfer of him to the custody of Country B. Dissent, at 769-70, 781. While our colleague would conclude that the Executive can forcibly transfer Doe to Country B in those circumstances, we respectfully disagree for the reasons explained in this opinion. a. A fundamental attribute of United States citizenship is a "right to ... remain in this country" and "to return" after leaving. Mandoli v. Acheson , 344 U.S. 133, 139, 73 S.Ct. 135, 97 L.Ed. 146 (1952). That right is implicated when the government seeks to forcibly transfer an American citizen from the United States to a foreign country. To effect such a transfer, the government must both (i) demonstrate that a treaty or statute authorizes the transfer, and (ii) give the citizen an opportunity to challenge the factual basis for the transfer. Valentine v. United States ex rel. Neidecker , 299 U.S. 5, 9, 57 S.Ct. 100, 81 L.Ed. 5 (1936) ; Collins v. Loisel , 259 U.S. 309, 316-17, 42 S.Ct. 469, 66 L.Ed. 956 (1922). The government's first argument in this case, though, is that a citizen loses both of those protections the instant he leaves U.S. territory. When a citizen sets foot outside the United States, the government says, the Executive can forcibly transfer him to the custody of any country having a "legitimate sovereign interest" in him. The transfer, the government emphasizes, would be "total." No. 18-5110, Gov't Second Supp. Br. 8. Following the citizen's transfer, then, he would be fully-and irrevocably-subject to the power of the foreign sovereign now holding him. i. The government's contention that it possesses that kind of transfer authority over an American citizen is centrally predicated on Munaf v. Geren , 553 U.S. 674, 128 S.Ct. 2207, which is itself predicated on Wilson v. Girard , 354 U.S. 524, 77 S.Ct. 1409. We disagree with the government's understanding of those decisions. In Wilson , William Girard, a U.S. soldier stationed in Japan, was accused by Japan of committing a homicide in its territory. 354 U.S. at 525-26, 77 S.Ct. 1409. The Army agreed to relinquish Girard to Japanese custody for pretrial detention. Id. at 526, 77 S.Ct. 1409. Girard filed a habeas petition, and the district court issued a preliminary injunction prohibiting the transfer. Id. The Supreme Court vacated the order and allowed the handover of Girard to Japanese custody. The Court began by recognizing that, as a general matter, a "sovereign nation has exclusive jurisdiction to punish offenses against its laws committed within its borders." Id. at 529, 77 S.Ct. 1409. Japan had voluntarily surrendered that prerogative in a security agreement with the United States that governed the treatment of U.S. soldiers stationed in Japan. But the agreement permitted the United States to cede back to Japan the authority to prosecute a service member in a given instance. Id. at 527-29, 77 S.Ct. 1409. In Girard's case, the United States had done just that. Id. at 529, 77 S.Ct. 1409. So the question, the Court said, was whether there was any "constitutional or statutory barrier" to the Executive (i) waiving the United States's jurisdiction and (ii) transferring Girard to Japan to face criminal prosecution. Id. at 530, 77 S.Ct. 1409. Finding no such barrier, the Court sanctioned Girard's transfer to Japanese custody. Id. In Munaf , the Court again applied the principle recognized in Wilson -i.e. , that, when a foreign country wishes to prosecute an American citizen who is within its borders for a crime he committed while there, the Executive can relinquish him to the country's custody. Munaf involved two American citizens who voluntarily traveled to Iraq and allegedly committed crimes while there. 553 U.S. at 679, 128 S.Ct. 2207. A multinational military coalition identified the two citizens as security risks, and they were held by U.S. military forces in Iraq "[p]ending their criminal prosecution for those offenses" in Iraqi courts. Id. at 705, 128 S.Ct. 2207 ; see id. at 681, 683, 128 S.Ct. 2207. Both of the citizens filed habeas petitions, asserting (i) that the Executive lacked the power to transfer them to Iraq's custody for criminal proceedings, and (ii) that transferring them thus would violate the Due Process Clause. Id. at 692, 128 S.Ct. 2207. The Court rejected their arguments and allowed the military to relinquish them to Iraqi custody. Id. at 705, 128 S.Ct. 2207. Relying on Wilson , the Court emphasized that a country has a "sovereign right to 'punish offenses against its laws committed within its borders.' " Id. at 692, 128 S.Ct. 2207 (quoting Wilson , 354 U.S. at 529, 77 S.Ct. 1409 ). That sovereign entitlement, the Court observed, was one that the Court had long and repeatedly recognized. Id. at 694-95, 128 S.Ct. 2207 (citing, e.g. , Schooner Exchange v. McFaddon , 11 U.S. (7 Cranch) 116, 3 L.Ed. 287 (1812) ; Neely v. Henkel , 180 U.S. 109, 21 S.Ct. 302, 45 L.Ed. 448 (1901) ; Kinsella v. Krueger , 351 U.S. 470, 76 S.Ct. 886, 100 L.Ed. 1342 (1956) ). An order prohibiting the Executive from transferring the two petitioners to Iraqi authorities would infringe that time-honored right. 553 U.S. at 697-98, 128 S.Ct. 2207. The Executive thus could transfer the petitioners to Iraqi custody without violating the Due Process Clause. Id. at 699-70, 128 S.Ct. 2207. In both Munaf and Wilson , the authority of the Executive to transfer U.S. citizens had no roots in any military authority over enemy combatants under the law of war. Wilson , after all, concerned "the peacetime actions of a [U.S.] serviceman," not the wartime actions of an enemy combatant. Id. at 699, 128 S.Ct. 2207. In Munaf , meanwhile, it is true that the alleged crimes involved insurgent acts committed in a time of war, for which both suspects had been designated "security internees" and one had been deemed an enemy combatant. See id. at 681-84, 705, 128 S.Ct. 2207. But the Court's recognition of the Executive's power to transfer the two men did not depend on those designations or on the nature of the alleged crimes. That is evident from the Court's heavy reliance on Wilson , a case having nothing to do with military authority in wartime. In accordance with that understanding, the Court in Munaf observed that "[t]hose who commit crimes within a sovereign's territory may be transferred to that sovereign's government for prosecution" even if the "crime at issue" is an inherently non-war offense like "embezzlement." Id. at 699-700, 128 S.Ct. 2207 (discussing Neely v. Henkel , 180 U.S. 109, 21 S.Ct. 302, 45 L.Ed. 448 (1901) ). To be sure, "there is hardly an exception to that rule when the crime" is "unlawful insurgency directed against an ally during ongoing hostilities." Id. at 700, 128 S.Ct. 2207. So while the war-related context in which the crimes arose in Munaf was not a necessary condition for the Executive to possess the transfer authority recognized in Wilson , that context of course did not diminish the Executive's authority. ii. In holding that the Executive had the power to transfer the Munaf petitioners, the Court distinguished its previous decision in Valentine v. United States ex rel. Neidecker , 299 U.S. 5, 57 S.Ct. 100. Because Doe chiefly relies on Valentine in arguing that the military lacks authority to transfer him to Country B, whereas the government centrally relies on Munaf in arguing the opposite, the Munaf Court's treatment of Valentine warrants our careful examination. In Valentine , three American citizens fled to New York City after being accused by France of committing crimes within its territory. Id. at 6, 57 S.Ct. 100. France requested the citizens' extradition, and U.S. officials arrested the three men. Id. The men then filed habeas petitions, arguing that, because the extradition treaty between the United States and France contained no obligation for either country to hand over its own citizens, the Executive lacked the power to extradite them. Id. The Court agreed, holding that the power to extradite "is not confided to the Executive in the absence of treaty or legislative provision." Id. at 8, 57 S.Ct. 100. Valentine thus establishes that the Executive's power to extradite a citizen from the United States to another country must come from a treaty or statute. Id. at 9, 57 S.Ct. 100 ; see Munaf , 553 U.S. at 704, 128 S.Ct. 2207. Relying on Valentine , Doe contends that the Executive cannot transfer him from U.S. custody to another country's custody unless the transfer is authorized by a treaty or statute. The petitioners in Munaf made the same argument in resisting their transfer to Iraqi custody. Munaf , 553 U.S. at 704, 128 S.Ct. 2207. The Court, though, found Valentine "readily distinguishable." Id. It explained that Valentine "involved the extradition of an individual from the United States." Id. The Munaf petitioners, by contrast, had "voluntarily traveled to Iraq and [were] being held there." Id. They were therefore "subject to the territorial jurisdiction of that sovereign, not of the United States." Id. The Court, for that reason, denied the contention that the Executive invariably "lacks the discretion to transfer a citizen absent a treaty or statute." Id. at 705, 128 S.Ct. 2207. Wilson , the Court said, "forecloses" that contention. Id. That is because the only conceivable authority in Wilson was the security agreement governing the treatment of U.S. service-members in Japan-which, while authorized by a treaty, was not itself a treaty or statute. Id. "Nevertheless," the Munaf Court observed, "in light of the background principle that Japan had a sovereign interest in prosecuting crimes committed within its borders," the Wilson Court had "found no 'constitutional or statutory' impediment to the United States's waiver of its jurisdiction" over Girard and its ensuing transfer of him to Japanese custody. Id. iii. Because Munaf and Wilson recognized the Executive's authority to transfer American citizens to foreign custody without having to satisfy Valentine 's treaty-or-statute rule, it is apparent that the Executive need not invariably meet the Valentine test to effect a forcible transfer. So some transfers of American citizens to foreign custody are governed by Valentine ; others are not. Into which of those camps does the proposed transfer of Doe to Country B fall? In arguing that it can forcibly transfer Doe, the government reads Valentine , Munaf , and Wilson to yield the following set of rules. Under Valentine , an American citizen in the United States cannot be forcibly transferred to a foreign country absent a statute or treaty (such as an extradition treaty) authorizing the transfer. But under Munaf and Wilson , the government says, once a citizen voluntarily leaves the United States, the Executive can pick her up and deliver her to any foreign country that has a "legitimate sovereign interest" in her. No. 18-5032, Gov't Opening Br. 27; No. 18-5032, Gov't Reply Br. 15; No. 18-5110, Gov't Supp. Br. 5; No. 18-5110, Gov't Second Supp. Br. 3. And a country's interest in a person qualifies as "legitimate," the government submits, if, under international law, the country would have "prescriptive jurisdiction" over her-that is, the power to prescribe legal rules regulating her pertinent conduct. No. 18-5032, Gov't Opening Br. 23 (citing Restatement (Fourth) of the Foreign Relations Law of the United States § 211 (Am. Law Inst. Draft No. 2, 2016) ); see also No. 18-5032, Gov't Reply Br. 15; No. 18-5110, Gov't Supp. Br. 4-5; No. 18-5110, Gov't Second Supp. Br. 4. We cannot accept the government's submission. Munaf and Wilson do not suggest a general prerogative on the part of the Executive to seize any American citizen voluntarily traveling abroad for forcible transfer to any country with some legitimate sovereign interest in her. Consider again the facts of Valentine . There was no doubt of the legitimacy of France's interest in the U.S.-citizen petitioners in that case: they had allegedly committed crimes in France. The Executive nonetheless lacked unilateral authority to "dispose of the[ir] liberty" by extraditing them. 299 U.S. at 9, 57 S.Ct. 100. That is because, the Court said, there is generally "no executive discretion to surrender [a person] to a foreign government, unless ... [a] statute or treaty confers the power." Id . Under the government's theory, though, everything would have changed the moment one of the Valentine petitioners voluntarily ventured outside the United States-say, on a family vacation to the Canadian side of Niagara Falls. At that moment, the unilateral "executive discretion" found lacking in Valentine ostensibly would have sprung to life, such that the person-though an American citizen-could have been seized by the Executive and forcibly transferred to France. Cf. United States v. Alvarez-Machain , 504 U.S. 655, 669-70, 112 S.Ct. 2188, 119 L.Ed.2d 441 (1992) (involving the seizure in Mexico (of a non-U.S. citizen) for transfer to the United States). That expansive vision of unilateral Executive power over a U.S. citizen who ventures abroad does not follow from Munaf and Wilson . Those cases did not involve a citizen forcibly transferred from one foreign country they voluntarily visited to the custody of another foreign country. The cases instead involved "the transfer to a sovereign's authority of an individual ... already ... in that sovereign's territory." Munaf , 553 U.S. at 704, 128 S.Ct. 2207. The petitioners in Munaf had "voluntarily traveled" to Iraq, id. at 681, 683, 128 S.Ct. 2207, and the petitioner in Wilson , an Army specialist, was stationed in Japan, 354 U.S. at 525-26, 77 S.Ct. 1409. They were "therefore subject to the territorial jurisdiction of [those] sovereign[s], not of the United States." Munaf , 553 U.S. at 704, 128 S.Ct. 2207. The petitioners in those cases, already present in the sovereign's territory, could be relinquished by the Executive to that sovereign for prosecution of offenses allegedly committed while there. That transfer power, the Munaf Court explained, is grounded in the receiving country's "territorial jurisdiction" over a person who has "voluntarily traveled" to its territory and is "being held there." Id. The government, though, reads Munaf and Wilson to embrace a transfer power extending to a receiving country's "prescriptive jurisdiction," not just its territorial jurisdiction. E.g. , No. 18-5032, Gov't Opening Br. 23. And a country's prescriptive jurisdiction under customary international law, the government emphasizes, extends to any "individual with a 'genuine connection' to the state, even when the individual is located outside the state's territory ." Id. (emphasis added); see also Restatement (Fourth) of the Foreign Relations Law of the United States § 211 (Draft No. 2, 2016). The government is surely correct that a sovereign's prescriptive jurisdiction-its power to regulate conduct-extends to persons located beyond its borders. The practice of extraditing individuals from abroad, and the existence of laws with extraterritorial reach, both illustrate the point. But the fact that a foreign country may have prescriptive jurisdiction over an American citizen who is outside its territory hardly means that, as long as the citizen is somewhere else abroad, the Executive has power to seize her and deliver her to that foreign country. Indeed, we know of no instance-in the history of the United States-in which the government has forcibly transferred an American citizen from one foreign country to another. (That includes the case of Amir Meshal, in which the government ardently denied a citizen's allegations that foreign officials, who had moved him from Kenya, to Somalia, to Ethiopia, were acting at the United States's behest. See Meshal v. Higgenbotham , 47 F.Supp.3d 115, 119 (D.D.C. 2014), aff'd , 804 F.3d 417 (D.C. Cir. 2015) ). Especially in habeas cases like this one, "history matters." Omar , 646 F.3d at 19. To that end, the absence of even a single known example of the unilateral power the Executive claims here is illuminating. Indeed, we are unaware of any involuntary transfer of a U.S. citizen from one foreign country to another even pursuant to a treaty or statute. There is all the more reason, then, to proceed with considerable caution before recognizing such a power as a unilateral (although apparently never-before-exercised) prerogative of the Executive. The implications of the government's reading of Munaf and Wilson amplify the reasons to reject it. Consider, for example, a U.S. citizen who becomes a journalist, travels to Thailand for a multi-year assignment, and, on returning to the United States, writes articles critical of the Thai King that are alleged to play some role in sparking demonstrations in Thailand. Thailand might well argue that she falls within its prescriptive jurisdiction. And its arguments would have force if, for instance, she underpaid her Thai taxes while there, or her articles were deemed to have had a "substantial effect" within Thailand. See Restatement (Fourth) of the Foreign Relations Law of the United States §§ 211 & cmt. f, 213 (Draft No. 2, 2016). If the government were right about Munaf and Wilson , then the moment the journalist stepped outside the United States, the Executive would have unilateral power to apprehend her and forcibly transfer her to Thailand if she were accused of violating Thai law. (Incidentally, there is a good reason to think the U.S.-Thai extradition treaty would not apply in that instance, given that it covers only "persons found in the territory of one of the Contracting Parties." Extradition Treaty, U.S.-Thai., art. 1, Dec. 14, 1983, S. Treaty Doc. No. 98-16.) By the government's logic, then, alleged breaches of the Thai tax code would authorize a forcible transfer. So too would alleged violations of Thailand's lèse-majesté statute-under which anyone who "defames, insults, or threatens the [Thai] King ... shall be punished with imprisonment of three to fifteen years." Crim. Code B.E. 2499 § 112 (1956), amended by Crim. Code (No. 17), B.E. 2547 (2003) (Thai.); see Lese-Majeste Explained: How Thailand Forbids Insult of its Royalty , BBC.com (Oct. 6, 2017) (discussing recent lèse-majesté prosecutions). We cannot accept that, if Thailand were to accuse the American journalist of underpaying taxes or penning articles critical of the King, the Executive would have unilateral power to apprehend and forcibly (and irrevocably) transfer her to Thai custody whenever she ventures outside the United States. Indeed, the implications of the government's argument are more far reaching still. Imagine that the journalist is a dual citizen of the United States and Thailand. If so, Thailand would have prescriptive jurisdiction over her regardless of any violation of Thai law, because, like all sovereigns, it has an "interest in retaining control over its nationals and residents, wherever they may be." Restatement (Fourth) of the Foreign Relations Law of the United States § 214 cmt. a (Draft No. 2, 2016). Under the government's theory, then, the Executive could forcibly transfer the journalist to Thai custody for any reason Thailand saw fit, including, say, that she would be a useful witness in a Thai trial. Cf. Blackmer v. United States , 284 U.S. 421, 436-37, 52 S.Ct. 252, 76 L.Ed. 375 (1932). Thailand's mere desire to have one of its citizens back cannot give the Executive the unilateral authority to forcibly transfer an American there, just because she steps outside the United States. After all, a dual citizen "is entitled to all the rights and privileges of [U.S.] citizenship." Perkins v. Elg , 307 U.S. 325, 349, 59 S.Ct. 884, 83 L.Ed. 1320 (1939). That includes the "right to return to and remain" in the United States after having left. Mandoli , 344 U.S. at 139, 73 S.Ct. 135. To be sure, if Thailand asked the United States for help in delivering the journalist to its custody (Thailand presumably would be reluctant to seize a U.S. citizen on its own), the Executive could (and presumably would) decline to do so as a matter of discretion. But the question for us is an antecedent one: whether, in the first place, the Executive would have the unilateral power to forcibly transfer an American citizen to another country merely because she travels abroad. We think the answer is no. The government emphasizes that, on the facts of this case, Doe is not just any citizen who traveled someplace abroad and is suspected of conduct like tax evasion. Rather, he went to an active battlefield; and Country B, a "coalition partner[ ] in an ongoing armed conflict" against ISIL, has, the government says, "an obvious and legitimate interest in taking custody of" him. No. 18-5032, Gov't Reply Br. 6. Those circumstances, however, do not give the Executive transfer power under Munaf and Wilson that it would otherwise lack. Munaf and Wilson , as explained, do not rest on the military's authority under the law of war. And we have declined to read those decisions to manifest a principle of prescriptive jurisdiction under which the Executive can forcibly transfer a U.S. citizen who has traveled abroad to any other country with a legitimate sovereign interest in her. That a country may have an especially important interest in a citizen-including by reason of her allegedly hostile actions against the country's interests in a time of war-does not affect that conclusion. Does this mean that the military necessarily is without power in a time of war to transfer an enemy combatant who is a U.S. citizen to an allied country's custody? No, it does not. It means that the authority to effect such a transfer does not come from the general transfer power recognized in Munaf and Wilson . The authority instead would come from the Executive's wartime powers under the law of war, a subject we turn to next. b. The government, as noted, has said in this case that its "determination that [Doe] is an enemy combatant ... is not the basis for the U.S. military's authority to transfer" him to Country B. No. 18-5032, Gov't Reply Br. 8. At the same time, though, the government has also said that "battlefield detainees" like Doe are "lawfully transferrable under the laws of war." Id. at 11; see also id. at 13 ("[P]etitioner's status as a U.S. citizen imposes no special constraints on the U.S. military's ability to transfer him consistent with the laws of war."); No. 18-5110, Gov't Second Supp. Br. 3 (arguing that transfer is permissible, in part because of "the Department of Defense's good-faith determination ... that [Doe] is an enemy combatant"). We now take up the latter facet of the government's claim of authority to transfer Doe: that it can do so pursuant to the Executive's wartime powers under the law of war. We conclude that the Executive does generally possess authority under the law of war to transfer an enemy combatant to the custody of an ally in the conflict. But that authority, we hold, could potentially support a transfer of Doe only if the government (i) demonstrates that it is legally authorized to use military force against ISIL, and (ii) affords Doe an adequate opportunity to challenge the Executive's factual determination that he is an ISIL combatant. i. The starting point for our analysis is the Supreme Court's decision in Hamdi v. Rumsfeld , 542 U.S. 507, 124 S.Ct. 2633, 159 L.Ed.2d 578 (2004). (Because the plurality in Hamdi issued the controlling opinion, which our court has treated as binding, see Al-Bihani v. Obama , 590 F.3d 866, 872 (D.C. Cir. 2010), we will treat the plurality opinion as that of the Court for purposes of this opinion.) There, the Court spoke directly to the military's authority over an American citizen under the law of war. The case involved Yaser Esam Hamdi, who, like Doe, was captured on a foreign battlefield, where the government alleged he had fought with the Taliban against the United States. Id. at 510, 512-13, 124 S.Ct. 2633. Hamdi, again like Doe, was a dual citizen of the United States and Saudi Arabia. See Man Held as Enemy Combatant to Be Freed Soon , CNN.com (Sept. 22, 2004.) The military initially detained Hamdi in Afghanistan and at Guantanamo Bay, and then, upon learning he was an American citizen, brought him to the United States for continued detention. 542 U.S. at 510, 124 S.Ct. 2633. Hamdi then filed a habeas petition seeking release from his military custody, alleging that his detention without criminal charge violated his rights under the Due Process Clause. Id. at 511, 124 S.Ct. 2633. The Court first held that the military had legal authority to detain Hamdi for the duration of the conflict in which he was captured. That power flowed from the 2001 Authorization for Use of Military Force (AUMF), Pub. L. No. 107-40, 115 Stat. 224. 542 U.S. at 517, 124 S.Ct. 2633. The 2001 AUMF authorized the President to "use all necessary and appropriate force against those nations, organizations, or persons [that] he determines planned, authorized, committed, or aided the terrorist attacks" of September 11, 2001. Id. at 510, 124 S.Ct. 2633 (quoting 115 Stat. 224, § 2(a) ). The Court found "no doubt" that Taliban combatants (like Hamdi was alleged to be) fit within that description. Id. at 518, 124 S.Ct. 2633. And the Court explained that detention of enemy combatants "for the duration of the particular conflict in which they were captured" is "so fundamental and accepted an incident to war as to be an exercise of the 'necessary and appropriate force' Congress ha[d] authorized the President to use." Id. The Court next addressed whether Hamdi's U.S. citizenship affected the Executive's power to detain him. On that issue, the Court found "no bar to this Nation's holding one of its own citizens as an enemy combatant." Id. at 519, 124 S.Ct. 2633. After all, "[a] citizen, no less than an alien, can be part of or supporting forces hostile to the United States or coalition partners and engaged in an armed conflict against the United States." Id. (internal citation and quotation marks omitted). Finally, the Court turned to "the question of what process is constitutionally due to a citizen who disputes his enemy-combatant status." Id. at 524, 124 S.Ct. 2633. The government argued that its determination to that effect should be subject to highly deferential review, solely to confirm the existence of some evidence supporting it. Id. at 527, 124 S.Ct. 2633. The government emphasized the "limited institutional capabilities of courts in matters of military decision-making in connection with an ongoing conflict." Id. The Court disagreed with the government. Because "due process demands some system for a citizen-detainee to refute his classification," the Court explained, "the proposed 'some evidence' standard [was] inadequate." Id. at 537, 124 S.Ct. 2633. Rather, "a citizen-detainee seeking to challenge his classification as an enemy combatant must receive notice of the factual basis for his classification, and a fair opportunity to rebut the Government's factual assertions before a neutral decisionmaker." Id. at 533, 124 S.Ct. 2633. That process, the Court observed, could potentially be afforded in a military proceeding. Id. at 538, 124 S.Ct. 2633. The Court also clarified, however, that "initial captures on the battlefield need not receive the process" the Court had outlined. Id. at 534, 124 S.Ct. 2633. Rather, that "process is due only when the determination is made to continue to hold" a combatant. Id. After Hamdi , we know that if there is legal authority to exercise military force against an enemy, that authority encompasses detention of an enemy combatant for the duration of the conflict. And we further know that the detention authority more generally extends to an enemy combatant who is an American citizen. But a citizen, Hamdi instructs, must have a meaningful opportunity to challenge the factual basis for his designation as an enemy combatant in accordance with the procedures set forth by the Court. ii. Whereas Hamdi addressed whether the Executive can detain an alleged enemy combatant who is a citizen, this case (at least at this stage) instead involves whether the Executive can transfer him to the custody of another country. That naturally raises two sets of questions. First, is the Executive's transfer authority (this case) on par with its detention authority ( Hamdi ) as a fundamental incident of waging war? Second, if so, is the Executive's exercise of transfer authority against a U.S. citizen subject to the same conditions attending the exercise of detention authority against a U.S. citizen? In other words, do transfer authority over citizens and detention authority over citizens essentially rise or fall together? We conclude they do. First , the military possesses settled wartime authority under the law of war to transfer enemy combatants to allied countries. That power, in the words of Hamdi , is "a fundamental incident of waging war," such that the Executive generally has the authority to transfer when it has legal authorization to engage in hostilities. Id. at 519, 124 S.Ct. 2633. Congress confirmed as much in the National Defense Authorization Act (NDAA) for Fiscal Year 2012, Pub. L. No. 112-81, 125 Stat. 1298 (Dec. 31, 2011). There, Congress elaborated on the authority conferred by the 2001 AUMF. It affirmed that the AUMF grants detention authority pending decision of an enemy combatant's "disposition under the law of war"; and it enumerated the available "dispositions" to include "[t]ransfer to the custody or control of the person's country of origin, any other foreign country, or any other foreign entity." Id. § 1021(a), (c). Congress thus expressly considers transfer of an enemy combatant to be one option available to the military under the law of war. The Department of Defense's directives are to the same effect. U.S. Dep't of Def., Directive No. 2310.01E, § 3.m (May 24, 2017). That understanding is firmly rooted in historical practice. "Throughout the 20th Century, the United States transferred or released hundreds of thousands of wartime alien detainees-some of whom had been held in America-back to their home countries, or in some cases, to other nations." Kiyemba v. Obama , 561 F.3d 509, 519-20 (D.C. Cir. 2009) (Kavanaugh, J., concurring). In World War I, for instance, the United States regularly transferred captured combatants to France, an ally. See George G. Lewis & John Mewha, History of Prisoner of War Utilization by the United States Army 1776-1945 , Dep't of the Army Pamphlet No. 20-213, at 59 (1955), available at https://cgsc.cdmhost.com. And in World War II, the United States transferred hundreds of thousands of Axis soldiers to allies like Belgium, France, and Luxembourg, where the soldiers were used as agricultural workers and underwent rehabilitation. Id. at 240-41. Transfers to allies were also commonplace during the Vietnam and Gulf Wars. See George S. Prugh, Law at War: Vietnam 1964-1973 , at 62 (1975); U.S. Dep't of Def., Office of Gen. Counsel, Law of War Manual at 633 n.742 (Dec. 2016). "Transfers," in short, "are a traditional and lawful aspect of U.S. war efforts." Kiyemba , 561 F.3d at 519 (Kavanaugh, J., concurring). Even if transfers of alien combatants have been a regular feature of warfare, does the traditional authority to transfer enemy combatants extend to a U.S. citizen? On this score, the historical evidence is sparse. As noted, we know of no instance in which the Executive has forcibly transferred a citizen from one foreign country to another; and that includes wartime transfers of enemy combatants. Hamdi , however, instructs that a traditional military power over enemy combatants in wartime should generally be assumed to encompass American citizens. The Court reasoned that a citizen, "no less than an alien," can be a part of an enemy force. 542 U.S. at 519, 124 S.Ct. 2633. For that proposition, the Court relied on its decision in Ex parte Quirin , 317 U.S. 1, 63 S.Ct. 2, 87 L.Ed. 3 (1942), in which it had upheld the military trial of a U.S. citizen for his unlawful belligerency in support of the enemy in World War II, id. at 30-31, 63 S.Ct. 2. To be sure, Justice Scalia, dissenting in Hamdi , discounted Quirin as "not [the] Court's finest hour." 542 U.S. at 569, 124 S.Ct. 2633 (Scalia, J., dissenting). He would have held that the military's wartime authority over enemy combatants-including, presumably, transfer authority-does not extend to a U.S. citizen (at least absent a suspension of the writ by Congress). See id. at 554, 124 S.Ct. 2633. The Court, though, adhered to Quirin notwithstanding Justice Scalia's critique. Id. at 522-23. It thus found no reason to exclude U.S. citizens from the Executive's fundamental authority under the law of war to detain enemy combatants for the duration of a conflict. Id. at 519, 124 S.Ct. 2633. Following the approach set out in Hamdi , we similarly see no basis for excluding a citizen-at least as a categorical matter-from the Executive's wartime authority to transfer enemy combatants. Hamdi referenced a Ninth Circuit decision upholding the Executive's power to detain, as a prisoner of war, a dual U.S.-Italian citizen who was a member of the Italian forces in World War II. Id. at 524, 124 S.Ct. 2633 (discussing In re Territo , 156 F.2d 142 (9th Cir. 1946) ); see also Ronald D. Rotunda, The Detainee Cases of 2004 and 2006 and Their Aftermath , 57 Syracuse L. Rev. 1, 13 n.73 (discussing Territo's dual citizenship). That decision also contemplated that he would be sent from the United States back to Italy at the war's end. See 156 F.2d at 144. True, that contemplated transfer would have been a "repatriation" to the enemy state, which, under the law of war, is distinct from a transfer to an ally (and which, presumably, would result in release rather than continued detention). Compare Geneva Convention (III) Relative to the Treatment of Prisoners of War, art. 12, Aug. 12, 1949, 6 U.S.T. 3316, with id. at art. 118. And Territo's repatriation might well have been voluntary, especially given his family and other connections to Italy (he sought release from his detention in the U.S., and the opinion gives no indication that he wanted to stay here if released). See 156 F.2d at 143. Still, Territo offers modest support for the conclusion that the Executive's power to transfer under the law of war applies to both aliens and citizens. And Hamdi , again, teaches that both aliens and citizens may be subject to the Executive's wartime authority. Second , having determined that the Executive has authority to transfer enemy combatants under the law of war, and that there is no blanket exemption from that power for U.S. citizens, we now assess whether Hamdi 's conditions on the exercise of detention authority equally govern any exercise of transfer authority. Those conditions, again, are that the Executive have legal authority to use military force against the relevant enemy (here, ISIL), and that the citizen be afforded the process laid out in Hamdi for challenging the factual determination that he is an enemy combatant. In considering whether transfer should be subject to those conditions, an initial point bears noting: the transfer of a citizen to another country's custody, unlike continued detention of that citizen, is irrevocable. Once the Executive relinquishes custody of an American citizen to another country, our government, and our laws-including our law's habeas guarantee, which a detainee can use to seek relief from detention over time-would be unavailable to her, perhaps in perpetuity. Decisions about the duration and conditions of her custody, and about the availability to her of a means of challenging her confinement, would be entirely up to the detaining sovereign. The government asserts that, when we assess a potential transferee's liberty interests, we cannot factor in her continued detention in the receiving country. That, the government says, follows from our holding in Kiyemba . 561 F.3d at 515-16. Here, though, the central issue is not the prospect of continued detention in Country B, but rather the forcible transfer itself, which would involuntarily send an American citizen from U.S. custody to the custody of another country. In that regard, Kiyemba is starkly different; there, it was undisputed that the detainees had no cognizable interest against being moved from Guantanamo to a foreign country. (Indeed, because transfer was the only relief available to the petitioners-who, as aliens, had no right to be released into the United States-they affirmatively sought to be moved to a foreign country. Id. at 519 n.5 (Kavanaugh, J., concurring) ). Here, by contrast, the transfer centrally implicates Doe's interest in not being forcibly moved into Country B's custody. Indeed, involuntary transfer of a citizen to the custody of another sovereign-including via extradition-undoubtedly involves fundamental liberty interests that can be vindicated in habeas corpus. E.g. , Valentine , 299 U.S. at 9, 57 S.Ct. 100 ("no executive prerogative to dispose of the liberty of the individual" by way of extradition); Landon v. Plasencia , 459 U.S. 21, 36, 103 S.Ct. 321, 74 L.Ed.2d 21 (1982). Cf. Sessions v. Dimaya , --- U.S. ----, 138 S.Ct. 1204, 1213, --- L.Ed.2d ---- (2018) (deportation from the United States can be viewed a more "severe penalty" for criminal misconduct than imprisonment in the United States). Given that transfers involve fundamental liberty interests, we see no basis for concluding that, for the transfer of a citizen (as opposed to the detention of a citizen), the Executive need not satisfy the Hamdi conditions. The 2012 NDAA is instructive in this regard. There, Congress set out four types of "disposition[s] under the law of war" that the Executive could choose for an enemy combatant, including "[d]etention under the law of war without trial until the end of the hostilities," and "[t]ransfer to the custody or control of the person's country of origin [or] any other foreign country." Pub. L. No. 112-81 § 1021(c)(1), (4). The statutory structure indicates that Congress saw transfer and detention as two options falling on largely the same plane-not as one option (transfer) broadly available in circumstances in which the other (detention) would not be. Significantly, our decisions draw an equivalence between transfer of citizens and detention of citizens. We have rejected the notion "that the Executive Branch may detain or transfer Americans or individuals in U.S. territory at will, without any judicial review of the positive legal authority for the detention or transfer ." Omar , 646 F.3d at 24 (emphases added). And we have said that "Congress cannot deny an American citizen or detainee in U.S. territory the ability to contest the positive legal authority (and in some situations, also the factual basis) for his detention or transfer unless Congress suspends the writ." Id. (emphasis added). For either "detention or transfer," then, an "American citizen" is entitled to challenge both "legal authority" and "factual basis," as Hamdi envisions. The government reads the just-quoted language from our decision in Omar to say that an American citizen can bring a "legal authority" or "factual basis" challenge to her "detention or transfer" only if she is in the United States. See No. 18-5032, Gov't Reply Br. 14. That is an unsustainable reading. Hamdi itself rejects the notion that it could "make a determinative constitutional difference" if an American citizen were detained overseas rather than in the United States. 542 U.S. at 524, 124 S.Ct. 2633. The Court understood that any such conclusion would "create[ ] a perverse incentive" to hold American citizens abroad. Id. The Omar court's reference to a challenge brought by "an American citizen or detainee in U.S. territory" thus plainly speaks to a challenge brought by a citizen anywhere or by an alien detained in U.S. territory (such as Guantanamo Bay). Omar , 646 F.3d at 24 (citing Boumediene v. Bush , 553 U.S. 723, 785-86, 128 S.Ct. 2229, 171 L.Ed.2d 41 (2008) ); see also Al Bahlul v. United States , 767 F.3d 1, 65 n.3 (D.C. Cir. 2014) (Kavanaugh, J., concurring in the judgment in part and dissenting in part) ("As a general matter, the U.S. Constitution applies to U.S. citizens worldwide and to non-U.S. citizens within the 50 states and the District of Columbia[.]"). There is no basis for thinking that a citizen relinquishes her right to bring a legal challenge to her detention-or, equivalently, to her transfer-if she is detained in (or transferred from) a foreign country. That is why the court in Omar went on to explain that Omar (one of the two Munaf petitioners), who was still being held in Iraq, had the requisite opportunity to contest the legal authority for his transfer. Id. That discussion would have been entirely unnecessary if he had no right to bring that challenge in the first place since he was held overseas. Consider the implications if there were, in fact, an asymmetry between transfer and detention, such that the Executive could transfer a U.S. citizen to another country without meeting the Hamdi conditions. With regard to legal authority, the military could irrevocably transfer a citizen thought to be an enemy combatant even if judicial review would have revealed that the Executive lacked lawful authority to use military force against the particular enemy. In that event, detainees in U.S. custody-and thus protected by U.S. law-would need to be released or criminally charged. But for those who had already been transferred to another country, an American court could not order their return or grant them comparable relief. With regard to a factual-basis challenge, the Hamdi Court sought to "meet the goal of ensuring that the errant tourist, embedded journalist, or local aid worker has a chance to prove military error." 542 U.S. at 534, 124 S.Ct. 2633. The procedural guarantees prescribed by the Court were intended to guard against an undue risk of an erroneous military determination. See id. But if the transfer of a citizen could be accomplished without affording her those protections, a risk of error thought unacceptable for continued detention would be present for an irrevocable transfer to another country. An "errant tourist" might then be protected against detention but unable to avoid an irrevocable transfer to another country's custody. Compare 31A Am. Jur. 2d Extradition § 120 (2d ed. 2018) (describing process granted to persons subject to extradition); 18 U.S.C. § 3191. The government, in that respect, relies on its having made a "good-faith determination, supported by extensive record evidence, that [Doe] is an enemy combatant." No. 18-5110, G