Treachery

Treachery is a longstanding prohibition in international humanitarian law (IHL). The 1907 Hague Regulations annexed to Hague Convention IV forbid combatants "to kill or wound treacherously individuals belonging to the hostile nation or army" (Article 23(b)). The concept was modernized and renamed perfidy in Article 37 of Additional Protocol I (1977) to the Geneva Conventions, which defines perfidy as "acts inviting the confidence of an adversary to lead him to believe that he is entitled to, or is obliged to accord, protection under the rules of international law applicable in armed conflict, with intent to betray that confidence."

Classic examples listed in API Article 37 include:

• Feigning surrender or an intent to negotiate under a flag of truce
• Feigning incapacitation by wounds or sickness
• Feigning civilian or non-combatant status
• Feigning protected status by misusing UN, neutral, or Red Cross/Red Crescent emblems

Treachery is distinguished from lawful ruses of war (camouflage, decoys, mock operations, misinformation), which do not invoke protected status and remain permitted under Article 37(2). The distinction matters because perfidy erodes the trust that makes protective rules workable: if combatants cannot rely on a white flag or a Red Cross armband, wounded soldiers and medics become targets.

Killing or wounding by perfidy is listed as a war crime in Article 8(2)(b)(xi) of the Rome Statute of the International Criminal Court for international armed conflicts, and at Article 8(2)(e)(ix) for non-international ones. The ICRC's 2005 Customary IHL Study identifies the prohibition as Rule 65, applicable in both international and non-international conflicts.

Note that in some domestic military codes and older treaties the word "treachery" is used interchangeably with "perfidy"; in others it can also denote treason against one's own state — a distinct concept in domestic criminal law.