Binding Armed Opposition Groups

Abstract This article considers how armed opposition groups fighting in an internal armed conflict are bound by the rules of international humanitarian law despite not being party to the relevant treaties. It assesses a number of explanations—customary international law, general principles of international humanitarian law, rules governing treaties and third parties and claims to succession—and argues that each has limited value. The ability of the state to legislate on behalf of all its individuals is considered the best explanation. This principle is explored and objections to it are countered. This article also examines the expressed commitment of armed opposition groups to the rules of international humanitarian law.