Duhaime's Law Dictionary

Unlawful Combatant Definition:

A combatant who does not act under orders or with a distinctive uniform and conceals arms and otherwise ignores the laws and customs of war.

Related Terms: Enemy Combatant, Prisoner of War

A terrorist is the classic example of an unlawful combatant.

Zachary defines an unlawful combatant as follows:

"An unlawful combatant is a person taking part in belligerent acts against a State, while not being part of a regular military force or subsidiary militias.

"Even an individual combatant who is part of a regular military force, and has forfeited his POW status through committing certain illegal acts, is regarded an unlawful combatant. The distinction between lawful and unlawful combatants is intended to uphold and emphasize the basic distinction between combatants and civilians. This distinction is, therefore, complementary to the basic distinction between 'combatant' and 'civilian'....

"The term unlawful combatant originates in World War II. In 1942, a group of German soldiers arrived by submarine at the American West-Coast, disguised in civilian clothes. They were captured by the Americans and brought to justice. The U.S. Supreme Court ruled unanimously that: "'The Laws of War distinguished between combatants and civilians, and between lawful combatants and unlawful ones. Lawful combatants are subject to capture and detention as POWs by the 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.'"1

Woolman writes, in her 2005 article:

"The term unlawful combatant is a term associated with the 1949 Geneva Convention and carries well-established international meaning. Convention III, relating to the Treatment of Prisoners of War (POW), contains criteria that separate civilians from lawful combatants and defines who should and should not be treated as a POW ...  including: a person must (1) be commanded by a person responsible for his subordinates; (2) have a fixed distinctive sign that is recognizable from a distance (be wearing a uniform); (3) be carrying arms openly; and (4) be conducting their operation in accordance with the laws and customs of war.

"The term unlawful combatant as applied in international law has been inferred from the definition of a lawful combatant.

"Unlawful combatants are either members of the regular forces or members of resistance guerrilla movements that do not fulfill the conditions of lawful combatants.

"The main legal impact of being a lawful combatant under the Geneva standards is the right to POW status. Unlawful combatants, although still targets of capture, are presumably not entitled to POW status."


  • NOTE 1: Ex parte Quirin, 317 US 1 (1942)
  • Woolman, Joanna, The Legal Origins of the Term Enemy Combatant Do Not Support Its Present Day Use, 7 J. L. & Soc. Challenges 145 (2005)
  • Zachary, Shlomy, Between the Geneva Conventions: Where Does the Unlawful Combatant Belong, 38 Isr. L. Rev. 378 (2005)

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