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A Project of The Annenberg Public Policy Center

Defining Enemy Combatant

Q: What is an enemy combatant?

A: “Enemy combatant” is shorthand for people who are fighting unlawfully. But no one is quite sure exactly what that means.


In relation to the current political debate over the Guantanamo prison, what is the legal definition of “enemy combatant”?


We can understand why one might be confused as to the actual definition of “enemy combatant.” It’s a question that has vexed philosophers, lawyers and constitutional scholars. Part of the problem is that “enemy combatant” is often used as shorthand for “unlawful enemy combatant.” But even distinguishing between lawful and unlawful enemy combatants doesn’t bring much additional clarity.

The Third Geneva Convention specifies a set of criteria that combatants must meet to be legal:

  • Be commanded by a person responsible for his subordinates
  • Have a fixed distinctive sign recognizable at a distance
  • Carry arms openly
  • Conduct their operations in accordance with the laws and customs of war

There are additional exceptions for certain classes of civilians, including those who “spontaneously take up arms to resist the invading forces, without having had time to form themselves into regular armed units, provided they carry arms openly and respect the laws and customs of war.”

On the other hand, the Military Commissions Act of 2006 defines a lawful enemy combatant as a member of the regular forces, a militia, a volunteer corps or an organized resistance movement belonging to a state (whether officially recognized or not) that is engaged in hostilities against the United States and who must

  • Wear a fixed distinctive sign recognizable at a distance
  • Carry his or her arms openly
  • Abide by the law of war

The Act does not provide any additional exemptions. Moreover, it also explicitly defines members of the Taliban, al Qaeda and associated forces as unlawful enemy combatants.

By and large, the Military Commissions Act of 2006 and the Third Geneva Convention will pick out the same people as lawful combatants. A U.S. Marine patrolling in Basra or a Russian soldier in Chechnya are both lawful combatants. A person who straps dynamite to his chest and blows up a cafe is not. Other cases, however, are less clear. A member of the Taliban militia, ordered to resist U.S. soldiers when they landed in 2001, would seem to be protected as lawful under the Third Geneva Convention. Under the Military Commissions Act of 2006, he wouldn’t be.

It’s also not clear which set of rules ultimately applies. The U.S. Constitution, in what scholars call the Supremacy Clause, specifies that treaties like the Third Geneva Convention are part of the supreme law of the land. But the Constitution also recognizes the right of Congress to pass laws. Scholars are divided as to which authority trumps the other. So until the Supreme Court rules on the issue (and it is under no obligation to do so), there is no clear legal definition of an enemy combatant, lawful or otherwise.


Bush, George W. “Message to the Congress of the United States.” 6 September 2006. 11 December 2007.

Geneva Convention (III) Relative to the Treatment of Prisoners of War.” 12 August 1949. Internnational Committee of the Red Cross. 11 December 2007.

Glaberson, William. “Military Judges Dismiss Charges for 2 Detainees.” New York Times 5 June 2007.

Public Law 109-366: Military Commissions Act of 2006.” 17 October 2006. Library of Congress: Military Legal Resources. 11 December 2007.