For the forty detainees who remain at Guantánamo Bay seventeen years after a military detention facility at the U.S. naval base opened,1 it must feel as though the War on Terror will never end. The success of their efforts to gain release, however, seems to depend on convincing courts that it already has. Recently, in Al-Alwi v. Trump,2 the D.C. Circuit upheld the continued detention of habeas petitioner Moath Hamza Ahmed Al-Alwi, who was designated an enemy combatant for fighting with the Taliban and transferred to Guantánamo in 2002.3 Al-Alwi argued that the government’s detention authority had “unraveled” due to the unprecedented duration and scope of the American war against the Taliban and al Qaeda.4 But the panel dismissed his claim on the basis that the conflict justifying his detention had not ended.5 In making that determination, the panel assessed whether hostilities on the ground were ongoing6 — a traditional standard under the law of war for measuring the lawful duration of detention.7 The court’s analysis, however, highlights the need for a new standard: as applied to the War on Terror, a conflict lacking some conventional boundaries, the end-of-hostilities test provides no serious check on indefinite detention.
In the week after September 11, 2001, Congress passed an Authorization for the Use of Military Force8 (AUMF) empowering the President to “use all necessary and appropriate force against those . . . he determines planned, authorized, committed, or aided the terrorist attacks.”9 That November, President George W. Bush invoked the AUMF and his Article II authority as grounds for the detention of al Qaeda members and others supportive of terrorism against the United States.10 Pursuant to that authority, the U.S. military brought the first set of detainees from the war in Afghanistan to Guantánamo in January 2002.11
Two years later, in Hamdi v. Rumsfeld,12 the Supreme Court affirmed the government’s asserted authority over the detainees.13 Justice O’Connor held for a plurality that detention of enemy combatants is a “fundamental incident of waging war” and thus encompassed in Congress’s authorization for the use of “necessary and appropriate force.”14 Under “longstanding law-of-war principles,” she noted, detention authority lasts for the duration of a conflict, so as to prevent combatants from returning to the battlefield.15 But Justice O’Connor allowed for the possibility that this “understanding may unravel” — “[i]f the practical circumstances of a given conflict are entirely unlike those of the conflicts that informed the development of the law of war.”16 Though she argued that no such unraveling in “this unconventional war” had occurred “as of [that] date,”17 the statement nonetheless seemed to suggest that the unique facts of a conflict could require courts to reevaluate traditional assumptions about war, like the end-of-detention yardstick.
Al-Alwi, a Yemeni citizen raised in Saudi Arabia,18 is one of the roughly 780 detainees who have been brought to Guantánamo since 2002.19 Prior to his capture in late 2001, Al-Alwi trained with the Taliban and fought in an al Qaeda–led combat unit in Afghanistan.20 In 2005, after three years of detention, Al-Alwi filed a habeas petition in the D.C. District Court challenging his designation as an enemy combatant; he claimed that he had no connection with al Qaeda and that the “minimal” support he provided the Taliban was not targeted at U.S. or coalition forces.21 No action was taken on Al-Alwi’s petition until 2008, however, when the Supreme Court held in a separate case that noncitizen Guantánamo detainees have a constitutional right to habeas corpus.22 After a hearing to assess Al-Alwi’s claim, the D.C. District Court denied his petition.23 Though no evidence was adduced that he had used arms against U.S. forces, the court held that his “close ties” to the Taliban and al Qaeda before and after the start of the U.S. war in Afghanistan made it more likely than not that he was “part of or supporting Taliban or al Qaeda forces.”24 The D.C. Circuit affirmed.25
In 2015, Al-Alwi filed a second habeas petition.26 This time, he did not contest his enemy-combatant designation.27 Instead, he claimed that the government’s detention authority had expired.28 Al-Alwi first argued that the “unprecedented” circumstances of the conflict in which he had participated — its duration, its geographic scope, and the variety of parties involved — had caused detention authority to “unravel,” as the Hamdi plurality had contemplated a decade prior.29 In the alternative, he argued that the conflict had ended, pointing to certain U.S. actions and statements as evidence.30 In particular, in a 2014 security agreement with Afghanistan, the United States declared that its forces would no longer conduct combat operations;31 and later that same year, President Barack Obama announced an end to the U.S. combat mission.32 In effect, then, Al-Alwi argued the United States had terminated its own detention authority.
The D.C. District Court denied Al-Alwi’s habeas petition again.33 Responding to his first argument, the court held that the government’s authority to detain had not unraveled.34 “To say the least,” the court noted, “the duration of a conflict does not somehow excuse it from longstanding law of war principles.”35 As for whether the conflict itself had ended, the court deferred to both the Executive’s and Congress’s determinations that hostilities in Afghanistan were ongoing, and thus concluded that Al-Alwi’s continued detention was (still) authorized under the AUMF.36
The D.C. Circuit affirmed.37 Writing for the panel, Judge Henderson38 rejected Al-Alwi’s argument that the government’s authority to detain enemy combatants had unraveled.39 She first noted that neither the AUMF nor the 2012 National Defense Authorization Act40— in which Congress affirmed that the AUMF authorizes detention through the end of hostilities41 — “places limits on the length of detention in an ongoing conflict.”42 She then characterized the notion of unraveling introduced by Justice O’Connor in Hamdi as “merely suggest[ing] the possibility that the duration of a conflict may affect” detention authority.43 Al-Alwi failed, Judge Henderson held, to identify any principle of international law that undermined the long-accepted rule that authority to detain persists through the end of active hostilities.44
As for whether those hostilities were actually ongoing, Judge Henderson noted that their termination is “a political act.”45 The Executive claimed that the AUMF-authorized conflict continued, and the record confirmed its claim.46 Absent any contrary word from Congress, Judge Henderson reasoned, the Executive’s representations controlled.47 She explained that neither the U.S.-Afghanistan security agreement nor a proclaimed end to the combat mission impacted the inquiry.48 Though the United States had transitioned to a new operation, a change in the conflict’s “form” did not “cut[] off AUMF authorization.”49 All that mattered was whether hostilities on the ground persisted.50 Because the United States remained in “active combat” with the Taliban and al Qaeda, its authority to detain Al-Alwi had not expired.51
Judge Henderson’s application of the end-of-hostilities inquiry is consistent with the understanding that detention is justified militarily only as long as fighting is ongoing. But as applied to the conflict in Afghanistan, this traditional understanding would permit seemingly open-ended detention authority. And even if active combat in Afghanistan ended, the authority could likely be sustained on the basis of the broader War on Terror. As applied to a purportedly global battlefield, the end-of-hostilities test provides no serious check on indefinite detention. Al-Alwi highlights the need for a standard that better balances the military purpose behind detention with humanitarian considerations underlying the law of war.
A factual end-of-conflict inquiry under the law of war was designed to balance the military purpose of detention with humanitarian interests requiring detainees “not be interned indefinitely.”52 The specific Geneva Convention provision cited by Justice O’Connor in Hamdi53 mandates that prisoners of war be released “without delay after the cessation of active hostilities”54 — in other words, “once the fighting is over,” such that the military justification underlying detention “no longer exists.”55 It was adopted after the Second World War as a response to governments that had held prisoners of war past the end of combat on the ground that the conflict had not been formally ended by treaty or armistice.56
In Afghanistan, however, where “fighting does not necessarily track formal timelines,”57 a purely factual inquiry helps sustain U.S. detention authority through varied stages of an open-ended conflict. The U.S. actions and statements highlighted by Al-Alwi, for instance, represented an effort to bring official combat operations to an end while still ensuring support sufficient for Afghanistan’s security.58 Given that fighting continued even at this reduced level of engagement, the “hostilities” requirement was easily met. Barring U.S. efforts to disengage from Afghanistan entirely, this state of affairs could persist indefinitely.59 Even a substantial lapse in fighting might not end the conflict under the law-of-war standard: “cessation of active hostilities” is a high bar, arguably requiring “clearly no probability of resumption of hostilities in a near future.”60 Afghanistan’s enduring instability, as evidenced by President Donald Trump’s stop-and-start efforts to withdraw U.S. troops from the country,61 suggests that this high bar is unlikely to be met anytime soon.
And even if hostilities in Afghanistan were to cease completely, the U.S. government might be able to maintain its current detention authority on the basis that the broader War on Terror was ongoing. The Hamdi plurality’s holding was tied to Afghanistan;62 accordingly, decisions on Guantánamo habeas petitions so far have “depended in almost every instance on the existence of a meaningful tie to ongoing hostilities in Afghanistan.”63 But the AUMF includes no geographic limits.64 Indeed, the U.S. government has used the Act to justify action in at least fourteen countries so far.65 It has authorized force against groups clearly associated with al Qaeda — the AUMF’s main target, but a group that has decentralized since 2001, giving birth to offshoots in the Middle East and Africa.66 And it has also relied on the AUMF in the fight against ISIS, on the ground that it is a “splinter group.”67 So long as hostilities continue in any of these geographic theaters, even if “against a succession of groups increasingly far removed from” al Qaeda,68 there will arguably always be a battlefield to which current Guantánamo detainees can return. Thus, under the traditional standard, their detention will remain perpetually justified. That standard “is premised on the possibility of an identifiable end of the conflict,”69 but the unconventional nature of today’s enemy means there simply may not be any such end to the War on Terror.70
Regardless of whether she envisioned this particular conflict as now qualifying for her “unraveling,” Justice O’Connor’s insight that the unique circumstances of a conflict could require revisiting traditional assumptions about war invites rethinking grounds for long-term detention today. Given that the current standard provides a weak check on indefinite detention, alternatives that better balance the military purpose of detention with humanitarian interests that also underlie the law of war should be considered. One would be to introduce some sort of specific time limit to guard against excessive detention.71 While released detainees could return to the battlefield, as have more than one hundred former Guantánamo inmates,72 the fact of detention might have reduced their fighting capacity.73 The rule could be a blunt one if applied strictly, but time limits distinguishing between categories of detainees — for instance, the able-bodied versus the infirm — might go some way toward alleviating that bluntness.74
In a similar vein, a second option, proposed by Professors Jack Goldsmith and Curtis Bradley, would turn on individualized determinations of whether an adversary fighter’s continued detention is justified.75 President Obama institutionalized a version of this approach in 2011 through the Periodic Review Board (PRB), a body of executive officials that reviews Guantánamo detentions.76 In 2015, the PRB determined that the detention of Al-Alwi “remain[ed] necessary to protect against a continuing significant threat to the security of the United States.”77 A drawback of this approach, however, especially to the extent that it lacks a check external to the Executive, is its potential for abuse and political interference.78
A third alternative would best grapple with the unprecedented nature of the conflict at hand, tying detention not to the duration of the War on Terror as a whole but rather to specific components of that broader armed conflict.79 In other words, it would tie detention authority to the precise conflict justifying its exercise. For instance, if fighting between the United States and the Taliban ended through a peace agreement — an increasingly likely, though far from certain, prospect80 — the U.S. government would forfeit authority to detain a former fighter like Al-Alwi.81 Given that the particular conflict best understood to justify his detention had ended, his detention would have to cease as well, regardless of any continued threat of terrorism by al Qaeda and its affiliates in other theaters.
In rejecting the unraveling claim, Judge Henderson noted Al-Alwi’s failure to advance “an alternative detention rule.”82 Given the absence of any such alternative under existing law, this failure is unsurprising. While the Al-Alwi court was correct to note that the duration of an armed conflict alone does not take the conflict out of the traditional detention framework, the practical realities of the War on Terror — in particular its global reach and the nature of the adversary — should require revisiting that framework. A factual inquiry as to whether hostilities continue provides an insufficient check on indefinite detention — a state of affairs obvious to enemy combatants who, like Al-Alwi, are seventeen years into their detention with no end in sight.