The definition of war crimes

Each belligerent Party bears State responsibility under international law for the conduct of all members of its armed forces: the State is obligated to maintain discipline, law and order at all times. All members of the armed forces are subject to the military and criminal codes of the State whom they serve, and in case of infraction they are liable to be prosecuted before military or civil courts of that State. As the four Geneva Conventions of 1949 for the Protection of War Victims lay down, contracting Parties ‘undertake to enact any legislation necessary to provide effective penal sanctions for persons committing, or ordering to be committed, any of the grave breaches’ defined in the Conventions.

However, self-discipline by a belligerent Party is not enough. Since time immemorial, international law has allowed other States – in particular, enemy States – to prosecute persons (especially, albeit not exclusively, members of the armed forces) for war crimes. Subsequent to the termination of World War II, war crimes committed in international armed conflicts have also been prosecuted before three international tribunals: the International Military Tribunal (IMT) at Nuremberg; the International Military Tribunal for the Far East (IMTFE) at Tokyo; and the International Tribunal for the Former Yugoslavia (ICTY). The IMT and the IMTFE concluded their operations in the 1940s, whereas the activities of the ICTY (established in 1993) are accelerating at the time of writing.