An act of perfidy is committed when a person invokes the provisions of the Geneva Conventions that are meant for the protection of persons, with the intent to betray, kill, injure, or capture an adversary. For instance, the improper use of the emblem of the Red Cross or any other protective emblems, flags, or uniforms (used, e.g., to invite and then betray the adversary’s trust) is forbidden, as is the act of feigning illness or pretending to be a civilian or other non-combatant (API Arts. 37–39 and 44).
According to the study on the rules of customary international humanitarian law published by the ICRC in 2005 (customary IHL study), ruses of war are not prohibited as long as they do not infringe a rule of international humanitarian law (Rule 57 of the customary IHL study). Besides, it is prohibited to kill, injure, or capture an adversary by resorting to perfidy in international and non-international armed conflicts (Rule 65).
The international law of armed conflict makes a distinction between ruses of war, which are not prohibited, and perfidy. The perfidious use of the distinctive emblem of the Red Cross or any other protective signs recognized by the 1949 Geneva Conventions and their 1977 Additional Protocols is a war crime (API Art. 85.3; Rome Statute, Art. 8.2.b.vii).
▸ Customary international law ▸ Distinctive (or protective) emblems, signs, or signals ▸ War crimes/Crimes against humanity
For Additional Information: Dinstein, Yoram. The Conduct of Hostilities under the Law of International Armed Conflict . Cambridge: Cambridge University Press, 2004.
Mulinen, Frederic de. Handbook on the Law of War for Armed Forces . Geneva: ICRC, 1989.
Oeter, Stefan. “Methods and Means of Combat.” In The Handbook of Humanitarian Law in Armed Conflicts , edited by Dieter Fleck, 199–202. Oxford: Oxford University Press, 1995.