International Humanitarian Law (IHL) is the jus in bello, or the law that regulates the conduct of armed conflicts. The International Committee of the Red Cross describes IHL as "the body of rules which, in wartime, protects people who are not or are no longer participating in the hostilities. Its central purpose is to limit and prevent human suffering in times of armed conflict. The rules are to be observed not only by governments and their armed forces, but also by armed opposition groups and any other parties to a conflict." Serious violations of this law are called war crimes.

Since World War II, the term IHL has also been used by scholars to include crimes against humanity insofar as that category of crimes has emerged from war crimes, even though it is now unrelated to war crimes and is applicable in times of war and peace; and genocide, insofar as that crime was originally a broader extension of crimes against...