Ruses of War

Ruses of war are deceptive practices a belligerent may use to confuse or mislead an enemy without violating international humanitarian law (IHL). They are explicitly permitted under Article 37(2) of Additional Protocol I (1977) to the Geneva Conventions, which defines them as "acts which are intended to mislead an adversary or to induce him to act recklessly but which infringe no rule of international law applicable in armed conflict, and which are not perfidious because they do not invite the confidence of an adversary with respect to protection under that law."

Classic examples listed in treaty commentary and military manuals include:

• Camouflage, decoys, mock operations, and dummy installations (e.g., inflatable tanks).
• Misinformation transmitted to the enemy, false orders, or fake radio traffic.
• Feigned attacks, retreats, or troop movements designed to draw the enemy out of position.
• Use of enemy codes, passwords, and signals intercepted in good faith.

Ruses are sharply distinguished from perfidy, which Article 37(1) prohibits. Perfidy involves feigning protected status — for instance, faking surrender, pretending to be a civilian, or misusing the Red Cross emblem — to kill, injure, or capture an adversary. The improper use of flags, military emblems, or uniforms of the enemy, neutrals, or the UN is also restricted under Articles 38–39 of AP I, and is listed as a war crime in Article 8(2)(b)(vii) of the Rome Statute of the International Criminal Court.

The line between a lawful ruse and unlawful perfidy turns on whether the deception abuses the enemy's confidence in a legal protection. Concealing a tank under netting is a ruse; raising a white flag to lure soldiers into an ambush is perfidy. Customary IHL, as catalogued in the ICRC's 2005 Customary International Humanitarian Law Study (Rules 57 and 65), confirms both the permission of ruses and the prohibition of perfidy in international and non-international armed conflicts alike.