	Introduction

Following the terrorist attacks of 9/11, Congress passed the Authorization for the Use of Military Force (AUMF), which granted the President the authority "to use all necessary and appropriate force against those ... [who] planned, authorized, committed, or aided the terrorist attacks" against the United States. As part of the subsequent "war on terror," many persons captured during military operations in Afghanistan and elsewhere were transferred to the U.S. Naval Station at Guantanamo Bay, Cuba, for detention and possible prosecution before military tribunals. Although nearly 800 persons were transported to Guantanamo from early 2002 through 2008, the substantial majority of Guantanamo detainees have ultimately been transferred to a third country for continued detention or release. Detainees who remain fall into three categories:
Persons who have been placed in preventive detention to stop them from returning to the battlefield (formerly labeled "enemy combatants" by the Bush Administration ). As a result, Guantanamo detainees may seek habeas review of the legality of their detention. 111-81 ) was signed into law, and modified rules governing military commissions. Efforts by the executive branch to close the facility have been hampered by a series of congressional enactments limiting executive discretion to transfer or release detainees into the United States, with the most significant limitations initially established by the Ike Skelton National Defense Authorization Act for FY2011 (2011 NDAA; P.L. By prohibiting funds from being used to transfer or release detainees into the United States, or to assist in the transfer or release of detainees into the country, these and subsequent similar acts seem to ensure that the Guantanamo detention facility remains open for the foreseeable future. Moreover, the measures appear to make military tribunals the only viable forum by which Guantanamo detainees could be tried for criminal offenses, as no civilian court operates within Guantanamo. 112-239 . The closure of the Guantanamo detention facility would raise a number of legal issues with respect to the individuals presently interned there, particularly if those detainees were transferred to the United States. This report provides an overview of major legal issues that are likely to arise in the event of executive and legislative action to close the Guantanamo detention facility. It discusses legal issues related to the transfer or release of Guantanamo detainees (either to a foreign country or into the United States), the continued detention of such persons in the United States, and the possible removal of persons brought to the United States. On March 7, 2011, President Obama issued Executive Order 13567, which establishes a process to periodically review whether the continued detention of a lawfully held Guantanamo detainee is warranted. These provisions restrict the use of funds (NDAA funds or funds under any act, respectively) to transfer a detainee to a foreign country or entity unless the Secretary of Defense certifies, with the agreement of the Secretary of State and in consultation with the Director of National Intelligence, that
(1) the government of the foreign country or the recognized leadership of the foreign entity to which the individual detained at Guantanamo is to be transferred—
(A) is not a designated state sponsor of terrorism or a designated foreign terrorist organization;
(B) maintains control over each detention facility in which the individual is to be detained ... ;
(C) is not, as of the date of the certification, facing a threat that is likely to substantially affect its ability to exercise control over the individual;
(D) has taken or agreed to take effective actions to ensure that the individual cannot take action to threaten the United States, its citizens, or its allies in the future;
(E) has taken or agreed to take such actions as the Secretary of Defense determines are necessary to ensure that the individual cannot engage or reengage in any terrorist activity; and
(F) has agreed to share with the United States any information that—
(i) is related to the individual or any associates of the individual; and
(ii) could affect the security of the United States, its citizens, or its allies; and
(2) includes an assessment, in classified or unclassified form, of the capacity, willingness, and past practices (if applicable) of the foreign country or entity in relation to the Secretary's certifications. These restrictions have continued through the 2013 NDAA and CAA without modification. The Consolidated Appropriations Act, 2010 ( P.L. The following sections discuss selected constitutional issues that may arise in the criminal prosecution of detainees, emphasizing the procedural and substantive protections that apply in different adjudicatory forums. In any event, the closure of the Guantanamo detention facility may raise complex legal issues, particularly if detainees are transferred to the United States. The nature and scope of constitutional protections owed to detainees within the United States may be different from the protections owed to those held elsewhere. The transfer of detainees into the country may also have immigration consequences.
Following the terrorist attacks of 9/11, Congress passed the Authorization for the Use of Military Force (AUMF), which granted the President the authority "to use all necessary and appropriate force against those ... [who] planned, authorized, committed, or aided the terrorist attacks" against the United States. Many persons subsequently captured during military operations in Afghanistan and elsewhere were transferred to the U.S. Naval Station at Guantanamo Bay, Cuba, for detention and possible prosecution. Although nearly 800 persons have been held at Guantanamo since early 2002, the substantial majority of Guantanamo detainees have been transferred to another country for continued detention or release. Those detainees who remain fall into three categories: (1) persons placed in non-penal, preventive detention to stop them from rejoining hostilities; (2) persons who face or are expected to face criminal charges; and (3) persons who have been cleared for transfer or release, whom the United States continues to detain pending transfer. Although the Supreme Court ruled in Boumediene v. Bush that Guantanamo detainees may seek habeas corpus review of the legality of their detention, several legal issues remain unsettled.
In January 2009, President Obama issued an Executive Order to facilitate the closure of the Guantanamo detention facility within a year. This deadline was not met, but the Administration has repeatedly stated its intent to close the facility. In March 2011, President Obama issued a new Executive Order establishing a process to periodically review whether the continued detention of a lawfully held Guantanamo detainee is warranted, which resulted in some 80 detainees being cleared for release and transfer to a foreign country. Efforts to transfer these prisoners and close Guantanamo have been hampered by a series of congressional enactments limiting executive discretion to transfer or release detainees into the United States, including, most recently, the National Defense Authorization Act for FY2013 (2013 NDAA; P.L. 112-239) and the Consolidated and Further Continuing Appropriations Act, 2013 (2013 CAA; P.L. 113-6 ). By prohibiting funds from being used to transfer or release detainees into the United States, or to assist in the transfer or release of detainees into the country, these acts seem to ensure that the Guantanamo detention facility remains open at least through the 2013 fiscal year, and perhaps for the foreseeable future. Moreover, the measures appear to make military tribunals the only viable forum by which Guantanamo detainees could be tried for criminal offenses, as no civilian court operates within Guantanamo, unless efforts to close the facility are successfully renewed. Upon signing each of these measures into law, President Obama issued a statement describing his opposition to the restrictions imposed on the transfer of Guantanamo detainees, and asserted that his Administration will work with Congress to mitigate their effect.
The closure of the Guantanamo detention facility would raise a number of legal issues with respect to the individuals formerly interned there, particularly if those detainees are transferred to the United States. The nature and scope of constitutional protections owed to detainees within the United States may be different from the protections owed to aliens held abroad. The transfer of detainees to the United States may also have immigration consequences. This report provides an overview of major legal issues likely to arise as a result of executive and legislative action to close the Guantanamo detention facility. It discusses legal issues related to the transfer of Guantanamo detainees (either to a foreign country or into the United States), the continued detention of such persons in the United States, and the possible removal of persons brought into the country. It also discusses selected constitutional issues that may arise in the criminal prosecution of detainees, emphasizing the procedural and substantive protections that are utilized in different forums (i.e., federal courts, court-martial proceedings, and military commissions).