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Detaining ISIS: Habeas and the Phantom Menace

By Professor Ernesto Hernández López, Chapman University, The Dale E. Fowler School of Law*.


The United States detained “John Doe,” an American citizen, in Iraq without any charge for over a year. He was release in October of 2018. Challenging this detention, Doe filed a habeas petition. It argued that detention is illegal because: statutory authority is needed to detain citizens and military detention depends on Congress authorizing the ISIS conflict. Doe contended that these conditions did not exist. The Government argued that detention was legal because Doe was an enemy combatant since he supported ISIS in Syria. This case, Doe v. Mattis, raised significant constitutional questions about citizens, executive detention, and deference in national security and foreign relations matters. But, much more remains at stake in terms of overseas power and military force. This Article argues that Doe’s prolonged detention is the expected result of legal ambiguities of American authority overseas.

Extraterritorial questions force courts to determine what law applies or not outside domestic borders.

Doe v. Mattis continued inquiries from Guantánamo detentions. A decade ago, the focus was Al Qaeda or the Taliban and alien detainees on territory under American control. Doe v. Mattis posed subsequent issues, regarding executive power and: citizen detention, if Congress authorized the ISIS conflict, and overseas habeas. This Article uses post-colonial and TWAIL (Third World Approaches to International Law) perspectives to examine military detention. These perspectives identify how prior legal reasoning shapes overseas authority. With Doe v. Mattis’s rulings on executive power and military detention adapt for new conflicts with changing enemies and no envisioned end.


On or near September 12, 2017 an American citizen surrendered himself to the Syrian Democratic Forces (“SDF”) somewhere near the Syria-Turkey border.(1) His actual name has not been disclosed officially, but he is known as “John Doe.” The New York Times has identified him. (2) The SDF transferred him to American forces, who along with the SDF, are part of an allied coalition fighting the Islamic State of Iraq and Syria (“ISIS”). Doe remained in American military detention from September 2017 to October 2018, over a year, without any criminal charge.(3) Soon after news of his detention, the American Civil Liberties Union filed a petition of habeas corpus on his behalf challenging the legality of his detention.(4) In this dispute, Doe v. Mattis, an appeals court affirmed(5) district court orders(6) barring Doe’s forced transfer to another country. As Doe waited for proceedings regarding if his detention was legal, on June 6, 2018 the Government notified the district court that it intended to return Doe to Syria, still in a civil war, where he was caught. (7) Meanwhile his custody passed the one-year mark without any proceedings or rulings on if this detention was legal. On October 28, Doe was transferred to Bahrain pursuant to a settlement, where he would be free, could keep his American citizenship, but with his American passport revoked.(8)

This Article describes Doe v. Mattis’s basic legal rulings, their constitutional significance, and their role in continuing flexible approaches to overseas American authority. In habeas filings for this case, the Government argued that it could legally detain Doe because the military determined that he was an enemy combatant. He has supported and/or was a member of ISIS, who traveled voluntarily to Syria to participate in the conflict.(9) In December and January, the United States attempted to transfer Doe out of Iraq. It is presumed that that this was to Saudi Arabia, since Doe is also a citizen of Saudi Arabia.(10) Like with his identity, any identification of the countries that could receive him remains under sealed court records.(11) Doe contended that he is a reporter who traveled to Syria to cover the conflict and that ISIS forced him to support them.(12) In habeas filings, Doe argued that his detention was illegal, because he is not an enemy combatant and that citizen detention requires express authorization from Congress. Specifically, his detention was unlawful since he is not an ISIS member and the military cannot detain him without statutory authorization from Congress.(13) Doe asked to be released, charged, or brought to the United States for trial.(14)

Developments in the U.S. District Court for the District of Columbia and the U.S. Court of Appeals for the D.C. Circuit for this case raised significant constitutional law issues. (15) These regard habeas remedies and judicial power in national security and foreign relations, executive detention during a conflict, and Congress’s legal authorization for war. These are traditional legal issues for detention, seen earlier in the War on Terror and in prior wars.(16) But, Doe v.

Mattis was far different. As described below, it helps shape what role courts and the Constitution play in the ISIS conflict, which comes seventeen years after Congress authorized a military response to the September 11, 2001 attacks.

Three circumstances from Doe v. Mattis questioned American law’s assumptions on military detention. First, because Doe is an American citizen he is entitled to more protections. Most habeas litigation in the War on Terror focused on alien detainees.(17) With foreign nationals, courts can more easily defer to what Congress or the Executive chose. Second, Congress has not expressly authorized a military campaign against ISIS.(18) Previously in Hamdi v. Rumsfeld, the Supreme Court determined that when Congress authorizes a military conflict it approves military detention for the duration of the conflict.(19) Congress issued Authorizations for Use of Military Force (“AUMFs”) in 2001 against Al Qaeda, the Taliban, and their supporters in response to the September 11 attacks and in 2002 to eliminate Saddam Hussein’s rule in Iraq.(20) It is debated if ISIS, and thereby military detention for its members and supporters, is covered by these AUMFs. Doe was detained as part of a military campaign that is not expressly authorized by Congress in terms of location, Syria, or in terms of its enemy, ISIS. The third complication involves time, for Doe’s detention and since Congress’s last approval for conflicts over a decade ago. It becomes difficult to justify deference to the Executive’s military authority the longer Doe was detained. Similarly, deference to congressional authorization becomes problematic as the conflict deviates from circumstances contemplated in 2001 and 2002. Claims of military urgency seem unrealistic, while wartime appears to be indefinite. These three circumstances created significant doctrinal questions about military conflict and habeas powers. Time, citizenship, and doubts about congressional authorization all confounded any application of War on Terror precedents to Doe v. Mattis.

This Article identifies three lessons from the habeas battle in Doe v. Mattis, regarding who can be militarily detained and how, where, and when this happens.(21) First, Doe’s citizenship and the conflict’s circumstances forced a habeas court into undefined legal terrain. Courts were forced to examine if the Executive can legally detain Doe. A lack of political authorization for the ISIS conflict created this. An AUMF expressly including ISIS as an enemy or specific to Syria would make it easier for courts to review the legality of detention in the ISIS conflict.(22) Otherwise, who is subject to detention and how, where, and when detention takes place remain less certain. Doe v. Mattis illustrates the cloudy path courts face when reviewing military detention overseas and when congressional authorization is unclear. Doe was finally released in October of 2018, with no district court proceeding or ruling regarding if the executive had the authority detain him. A series of pleadings for these issues were submitted between January and March. They addressed citizen detention, the Non Detention Act (NDA), two AUMFs and ISIS, Congress authorizing the ISIS conflict, and the executive’s inherent authority.(23) Effectively, the Government stopped pursuing these arguments and the district court did not have to rule on these issues, leaving much of the cloudy path still unclear.(24)

Second, the dispute confronted habeas anomalies raised by Guantánamo detainees since 2002. This regards: if habeas powers include court orders to stop detainee transfers,(25) does detention become indefinite and illegal when a conflict lacks any envisioned end,(26) and if citizen detention is legal without any charge or opportunity to contest custody. (27) These issues for ongoing Guantánamo detentions remain unclear and prior jurisprudence may be inconclusive at best. In a statement agreeing with certiorari review denial in 2014, Justice Breyer explained that it is uncertain if detention is authorized for persons “not engaged in an armed conflict against the United States” and if the 2001 AUMF or the Constitution “limits the duration of [base] detention.”(28) For Breyer, these doubts exist despite the “limited category” of AUMF detention approved in Hamdi. (29)

Suggested Citation:

Hernandez Lopez, Ernesto, Detaining ISIS: Habeas and the Phantom Menace (September 22, 2018). Oklahoma Law Review, Vol. 71, Forthcoming. Available at SSRN:

*This is an abridged version (November 8, 2018) and will be included in a forthcoming issue of the Oklahoma Law Review.


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