Were Miranda Rights Read To Faisal Shahzad? John McCain Hopes Not

The term unlawful combatant has been used for the past century in legal literature, military manuals and case law.[3] The term "unlawful combatants" was first used in US municipal law in a 1942 United States Supreme Court decision in the case ex parte Quirin.[28] In this case, the Supreme Court upheld the jurisdiction of a U.S. military tribunal over the trial of several German saboteurs in the US. This decision states (emphasis added and footnotes removed):

By universal agreement and practice, the law of war draws a distinction between the armed forces and the peaceful populations of belligerent nations and also between those who are lawful and unlawful combatants. Lawful combatants are subject to capture and detention as prisoners of war by opposing military forces. Unlawful combatants are likewise subject to capture and detention, but in addition they are subject to trial and punishment by military tribunals for acts which render their belligerency unlawful. The spy who secretly and without uniform passes the military lines of a belligerent in time of war, seeking to gather military information and communicate it to the enemy, or an enemy combatant who without uniform comes secretly through the lines for the purpose of waging war by destruction of life or property, are familiar examples of belligerents who are generally deemed not to be entitled to the status of prisoners of war, but to be offenders against the law of war subject to trial and punishment by military tribunals.

The validity of this case, as basis for denying prisoners in the War on Terrorism protection by the Geneva Conventions, has been disputed.[29][30][31] A report by the American Bar Association commenting on this case, states:

In the wake of the September 11, 2001 attacks, the United States Congress passed a resolution known as the Authorization for Use of Military Force (AUMF) on 18 September 2001. In this, Congress invoked the War Powers Resolution and stated:

That the President is authorized to use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organizations or persons, in order to prevent any future acts of international terrorism against the United States by such nations, organizations or persons.[35]

Using the authorization granted to him by Congress, on 13 November 2001, President Bush issued a Presidential Military Order: "Detention, Treatment, and Trial of Certain Non-Citizens in the War Against Terrorism"[36] which allowed "individuals ... to be detained, and, when tried, to be tried for violations of the laws of war and other applicable laws by military tribunals", where such individuals are a member of the organization known as al Qa'ida; or has conspired or committed acts of international terrorism, or have as their aim to cause, injury to or adverse effects on the United States, its citizens, national security, foreign policy, or economy. The order also specifies that the detainees are to be treated humanely.

The length of time for which a detention of such individuals can continue before being tried by a military tribunal is not specified in the military order. The military order uses the term "detainees" to describe the individuals detained under the military order. The U.S. administration chooses to describe the detainees held under the military order as "illegal enemy combatants".