A war crime is a breach of the international law of armed conflict that is regarded as so serious that it entails not just state responsibility, but individual criminal responsibility. Unlike crimes against humanity, there is no general requiremen that a war crime take place in the context of widespread, massive, or systematised criminality; instead, such a crime may be a single, isolated incident, so long as it occurs in the context of an armed conflict. Articles 2 and 3 of the Statute of the International Criminal Tribunal for the former Yugoslavia (ICTY) set forth two classic categories of war crimes. Article 2 lists the ‘grave breaches’ of the 1949 Geneva Conventions, punishable only when committed in international armed conflict:

Article 2: Grave breaches of the Geneva Conventions of 1949

The International Tribunal shall have the power to prosecute persons committing or ordering to be committed grave breaches of the Geneva Conventions of 12 August 1949, namely the following acts against persons or property protected under the provisions of the relevant Geneva Convention:

1. wilful killing;

2. torture or inhuman treatment, including biological experiments;

3. wilfully causing great suffering or serious injury to body or health;

4. extensive destruction and appropriation of property, not justified by military necessity and carried out unlawfully and wantonly;

5. compelling a prisoner of war or a civilian to serve in the forces of a hostile power;

6. wilfully depriving a prisoner of war or a civilian of the rights of fair and regular trial;

7. unlawful deportation or transfer or unlawful confinement of a civilian;

8. […]