The Gamble That Isn’t: Trump’s Ability to Detain Members of ISIL

James A. D’Cruz* (Published March 3, 2017)

Andrew Hanson, in his piece The GITMO Gamble, briefly considered whether the Obama Administration had given President Trump the key to detaining members of ISIL in the Guantanamo Bay Detention Facility (GITMO). Hanson expresses concern about whether the courts will accept the Obama Administration’s expanded interpretation of the 2001 AUMF, and posits that the courts’ rejection of the interpretation would require Congress to pass a new authorization. However, it is very unlikely that any court would hold that President Trump lacks the authority to detain members of ISIL at GITMO.

The first inquiry in determining whether President Trump has the authority to detain members of ISIL at GITMO is whether he has been authorized by Congress or his independent Article II powers to conduct hostilities against the group. This analysis begins with the Supreme Court opening the door for an expansive reading of the 2001 AUMF in its decision of Hamdi v. Rumsfeld.[1] After ISIL established itself as a threat, President Obama purported that the authority to conduct hostilities against the Islamic State stemmed from the 2001 AUMF, as ISIL constitutes an “associated force” of Al-Qaeda.

The phrase “associated forces” was introduced by the Deputy Secretary of Defense’s Order on July 7, 2004, which set forth the definition of an “enemy combatant” for use by Combatant Status Review Tribunals (CSRTs).[2] Under this definition, an “enemy combatant” is “an individual what was part of or supporting Taliban or Al Qaida forces, or associated forces that are engaged in hostilities against the United States or its coalition partners.”[3] This definition was seemingly conflated with the 2001 AUMF by the D.C. Court of Appeals, constructing the current reading of the authorization to include “associated forces.” However, even if this interpretation of Hamdi and Parhat is mistaken, Congress nevertheless authorized the use of force against “associated forces” in the 2006 Military Commissions Act and the National Defense Authorization Act (NDAA) for Fiscal Year 2012.[4] Although the NDAA is distinct from the 2001 AUMF, the language in the NDAA has been purported to amend the 2001 authorization to permit the use of force against “associated forces.”[5]

Even if the 2001 AUMF proves unavailing, the Trump Administration may rely on the 2002 Iraq AUMF or the Executive Branch’s Article II powers. President Obama claimed that because ISIL had a presence in Iraq and threatened the stability of the new government, the 2002 AUMF and the 2001 AUMF permitted the conduct of hostilities in Iraq and Syria.[6] Although President Obama sought to repeal the 2002 authorization in his proposed ISIL AUMF, Congress failed to enact the new authorization.[7] Beyond this, ISIL’s continued existence represents a very serious threat to the United States. President Trump may rely on his Commander-in-Chief power to defend the United States from the threat of terrorist attacks against the United States or its interests as was done by President Harry Truman when he ordered the invasion of Korea. This right is bolstered by Article 51 of the U.N. Charter.[8]

After the jus ad bellum requirements of the International Law of Armed Conflict are satisfied, the conflict with ISIL is likely classified as a non-international armed conflict, giving the United States considerable discretion in its use of force. The United States argues that it may use force against belligerents who are directly participating in hostilities, have a continuous combat function, or are members of terrorist organizations.[9] If the President has the power to kill these belligerents under the Law of Armed Conflict, he must have the authority to detain those individuals—surely a lesser punishment.[10] Therefore, the Trump Administration, not bound by the Prisoner of War provisions in Geneva Convention IV, can detain members of ISIL either at detention facilities in or near the zone of hostilities or at GITMO.

There is simply nothing special about GITMO that would prevent individuals from being detained there, rather than at detention facilities in Iraq or Syria. Customary International Law has long recognized the right to detain individuals in armed conflict. Without this power, belligerents would be incentivized to exercise only deadly force in conflicts—a notion repugnant to the spirit of international law. For the courts to suddenly hold that President Trump cannot detain members of ISIL would be to declare that President Obama acted beyond his constitutional authority and committed crimes against the state, if not international war crimes. The ramifications are simply too great, and courts have never taken such a drastic measure in administrations past. Ideally, Congress would authorize a new AUMF against ISIL, but such authorization is likely the stuff of fairy tales in such a divided Congress, and is probably not required under the current interpretations of the 2001 and 2002 AUMFs.

* J.D. Candidate, Harvard Law School, 2017; B.A., Florida International University, 2014; National Security Certificate, Florida International University, 2014.

[1] 542 U.S. 507, 518 (2004) (citing 115 Stat. 224) (“The AUMF authorizes the President to use “all necessary and appropriate force” against “nations, organizations, or persons” associated with the September 11, 2001, terrorist attacks.”).
[2] See Parhat v. Gates, 532 F.3d 834, 837–38 (D.C. Cir. 2008).
[3] See id. (citing to the Deputy Secretary of Defense Order and Secretary of the Navy Memorandum) (emphasis added).
[4] See Al-Bihani v. Obama, 590 F.3d 866, 872 (D.C. Cir. 2010) (citing § 948a (1)(A)(i) of the 2006 Military Commissions Act); see also Al-Adahi v. Obama, 613 F.3d 1102, 1103 (D.C. Cir. 2010), cert. denied, 131 S. Ct. 1001 (2011); Anwad v. Obama, 608 F.3d 1, 11–12 (D.C. Cir. 2010), cert. denied, 131 S. Ct. 1814 (2011); Pub. L. 112-81 § 1021 (Dec. 31, 2011).
[5] See Matthew C. Weed, 2001 Authorization for Use of Military Force: Issues Concerning Its Continued Application 15, Congressional Research Service (April 14, 2015) available at
[6] See id. at 5.
[7] See id.see also Matt Fuller, Why Won’t Congress Declare War on ISIS?, The Huffington Post, Dec. 15, 2015,
[8] See U.S. Const. art. II § 2; see also U.N. Charter, art. 51 (protecting the “inherent right . . . tof self-defense.”).
[9] See U.S. Dep’t of Def., Law of War Manual §§ 5.8.1, 5.8.2 (Dec. 2016 Update); see also Additional Protocol I, art. 51 (3) (“Civilians shall enjoy the protection afforded by this Section, unless and for such time as they take a direct part in hostilities.”).
[10] See Hamdi, 542 U.S. at 518 (2004).