International Humanitarian Law

International humanitarian law (IHL), or the law of armed conflict, is the law that regulates the conduct of armed conflicts (jus in bello). It comprises "the Geneva Conventions and the Hague Conventions, as well as subsequent treaties, case law, and customary international law." It defines the conduct and responsibilities of belligerent nations, neutral nations and individuals engaged in warfare, in relation to each other and to protected persons, usually meaning civilians.

Serious violations of international humanitarian law are called war crimes. International humanitarian law, jus in bello regulates the conduct of forces when engaged in war or armed conflict. It is distinct from jus ad bellum which regulates the conduct of engaging in war or armed conflict and includes crimes against peace and of war of aggression. Together the jus in bello and jus ad bellum comprise the two strands laws of war governing all aspects of international armed conflicts.

The law is mandatory for nations bound by the appropriate treaties. There are also other customary unwritten rules of war, many of which were explored at the Nuremberg War Trials. By extension, they also define both the permissive rights of these powers as well as prohibitions on their conduct when dealing with irregular forces and non-signatories.

International humanitarian law operates on a strict division between rules applicable in international armed conflict and those relevant to armed conflicts not of an international nature. This dichotomy is widely criticized.