The renewal of military commission proceedings against Khalid Sheik Mohammad and four others for their alleged involvement in the 9/11 terrorist attacks has focused renewed attention on the differences between trials in federal court and those conducted by military commission. The decision to try the defendants in military court required a reversal in policy by the Obama Administration, which had publicly announced in November 2009 its plans to transfer the five detainees from the U.S. Naval Station in Guantanamo Bay, Cuba, into the United States to stand trial in the U.S. District Court for the Southern District of New York for criminal offenses related to the 9/11 attacks. The Administration's plans to try some Guantanamo detainees in federal civilian court proved controversial, and Congress responded by enacting funding restrictions which barred any non-citizen held at Guantanamo from being transferred into the United States for any purpose, including prosecution. These restrictions, which have been extended for the duration of FY2014, effectively make military commissions the only viable option for trying detainees held at Guantanamo for the foreseeable future, and have resulted in the Administration choosing to reintroduce charges against Mohammed and his co-defendants before a military commission. While military commission proceedings have been instituted against a number of suspected enemy belligerents held at Guantanamo, the Obama Administration has opted to bring charges in federal criminal court against many terrorist suspects held at locations other than Guantanamo. On July 5, 2011, Somali national Ahmed Abdulkadir Warsame was brought to the United States to face terrorism-related charges in a civilian court, after having reportedly been detained on a U.S. naval vessel for two months for interrogation by military and intelligence personnel. Some argued that Warsame should have remained in military custody abroad and face trial before a military commission, while others argued that he should have been transferred to civilian custody immediately. Similar controversy also arose regarding the arrest by U.S. civil authorities and subsequent prosecution of Umar Farouk Abdulmutallab and Faisal Shahzad, who some argued should have been detained and interrogated by military authorities and tried by military commission. This report provides a brief summary of legal issues raised by the choice of forum for trying accused terrorists and a chart comparing authorities and composition of the federal courts to those of military commissions. A second chart compares selected military commissions rules under the Military Commissions Act (MCA), as amended by the Military Commissions Act of 2009, to the corresponding rules that apply in federal court. This chart follows the same order and format used in CRS Report RL31262, Selected Procedural Safeguards in Federal, Military, and International Courts , to facilitate comparison with safeguards provided in international criminal tribunals. For similar charts comparing military commissions as envisioned under the MCA, as passed in 2006, to the rules that had been established by the Department of Defense (DOD) for military commissions and to general military courts-martial conducted under the Uniform Code of Military Justice (UCMJ), see CRS Report RL33688, The Military Commissions Act of 2006: Analysis of Procedural Rules and Comparison with Previous DOD Rules and the Uniform Code of Military Justice , by [author name scrubbed]. For a comparison of the rules established by the MCA 2006 with those found in the MCA 2009 and to the rules that apply to courts martial under the UCMJ, see CRS Report R41163, The Military Commissions Act of 2009 (MCA 2009): Overview and Legal Issues , by [author name scrubbed]. For additional analysis of issues related to the disposition of Guantanamo detainees, including possible trials in federal or military courts, see CRS Report R40139, Closing the Guantanamo Detention Center: Legal Issues , by [author name scrubbed] et al. On January 22, 2009, President Barack Obama issued an executive order requiring that the Guantanamo detention facility be closed no later than a year from the date of the order. The order established a task force ("Guantanamo Task Force") to review all Guantanamo detentions to assess whether each detainee should continue to be held by the United States, be transferred or released to another country, or be prosecuted by the United States for criminal offenses. Ongoing military commissions were essentially halted during this review period, although some pretrial proceedings continued to take place. One detainee, Ahmed Ghailani, was transferred in June 2009 to the Southern District of New York for trial in federal court on charges related to his alleged role in the 1998 East Africa Embassy bombings, and was subsequently convicted and sentenced to life imprisonment. President Obama's Detention Policy Task Force issued a preliminary report July 20, 2009, reaffirming that the White House considers military commissions to be an appropriate forum for trying some cases involving suspected violations of the laws of the war, although federal criminal court would be the preferred forum for any trials of detainees. The disposition of each case referred for criminal prosecution is to be assigned to a team comprised of DOJ and DOD personnel, including prosecutors from the Office of Military Commissions. The report also provided a set of criteria to govern the disposition of cases involving Guantanamo detainees. In addition to "traditional principles of federal prosecution," the protocol identifies three broad categories of factors to be taken into consideration: Strength of interest, namely, the nature and gravity of offenses or underlying conduct; identity of victims; location of offense; location and context in which individual was apprehended; and the conduct of the investigation. Efficiency, namely, protection of intelligence source and methods; venue; number of defendants; foreign policy concerns; legal or evidentiary problems; efficiency and resource concerns. Other prosecution considerations, namely, the extent to which the forum and offenses that can be tried there permit a full presentation of the wrongful conduct, and the available sentence upon conviction. On November 13, 2009, Attorney General Holder announced the decision to transfer five "9/11 conspirators" to the Southern District of New York to stand trial, and charges that had previously been brought against these individuals before military commissions were withdrawn without prejudice in January 2010. On January 22, 2010, the Guantanamo Task Force issued its final report concerning the appropriate disposition of each detainee held at Guantanamo. The Task Force concluded that 36 detainees remained subject to active criminal investigations or prosecutions; 48 detainees should remain in preventive detention without criminal trial, as they are "too dangerous to transfer but not feasible for prosecution"; and the remaining detainees may be transferred, either immediately or eventually, to a foreign country. The Administration's plans to bring Khalid Sheik Mohammed and other Guantanamo detainees into the United States proved controversial. Beginning in 2009, Congress began placing funding restrictions in annual appropriations and authorization measures to limit executive discretion to transfer or release Guantanamo detainees into the United States. Because no civilian court operates at Guantanamo, these limitations have effectively made military commissions the only viable option for trying Guantanamo detainees for criminal activity for the foreseeable future. In March 2011, Secretary of Defense Robert Gates announced that the government would resume the filing of charges before military commissions at Guantanamo. Shortly thereafter, Attorney General Eric Holder announced the Obama Administration's reversal of its decision to bring Khalid Sheik Mohammed and his alleged co-conspirators into the United States to face trial in federal court, and stated that they would instead be tried before a military commission at Guantanamo. In April 2012, charges were referred to a military commission against Khalid Sheikh Mohammed, Walid Bin Attash, Ramzi Bin Al Shibh, Ali Abdul-Aziz Ali, and Mustafa Ahmed Al Hawsawi for their alleged involvement in the 9/11 attacks. In October 2012, the U.S. Court of Appeals for the D.C. Circuit, in its first case of an appeal from a military commission conviction, reversed the conviction of Salim Hamdan after determining that Congress did not intend for the offenses it defined in the MCA to apply retroactively ( Hamdan II ). Because the court agreed that the crime of material support for terrorism did not exist as a war crime under the international law of war at the time the relevant conduct occurred (a requirement under the military commissions statute in effect at the time ), it vacated the decision below of the Court of Military Commissions Review (CMCR), which had unanimously affirmed Hamdan's conviction. Some have noted the prevalence of the charge of material support for terrorism in military commission cases to date and question the continued viability of the military commission system in light of this decision. The government did not appeal the decision to the Supreme Court. Instead, the government is appealing the second CMCR appeal of a final verdict, Al Bahlul v. United States. When that case reached the D.C. Circuit on appeal, the government essentially asked the appellate court to overturn Al Bahlul's conviction on the basis that Hamdan II provided binding precedent on the question presented, namely, the validity of convictions for conspiracy, solicitation, and material support of terrorism for conduct preceding passage of the Military Commissions Act (MCA) in 2006. ( Hamdan II did not address conspiracy or solicitation, but the government conceded that these offenses do not constitute universally recognized violations of the international law of war.) The court complied with the request in a per curiam order. The government sought and was granted a rehearing en banc in the Bahlul case. U.S. law provides for the trial of suspected terrorists, including those captured abroad, in several ways. Those who are accused of violating specific federal laws are triable in federal criminal court. Provisions in the U.S. Criminal Code relating to war crimes and terrorist activity apply extraterritorially and may be applicable to some detainees.