A war crime is a violation of the laws of war. The legal understanding of war crimes has been codified in several multilateral treaties, most notably the Geneva Conventions. More recently, the most comprehensive legal statement on war crimes was the Rome Statute of the International Criminal Court.
To be liable for a war crime, the victim must be protected under the Geneva Conventions. GC I, II, and III apply to soldiers, while GC IV applies to civilians and "unlawful combatants."
The following acts are war crimes under Rome Statute Article 8:
- wilful killing;
- biological experiments;
- unjustified destruction and appropriation of property;
- conscripting POWs;
- denying POWs a fair trial;
- unlawful deportation and transfer;
- unlawful confinement;
- taking of hostages;
- intentional attacks against civilians;
- intentional attacks against non-military targets;
- intentional attacks against peacekeepers or humanitarian aid groups;
- killing or wounding combatants who have surrendered;
- employing poisoned weapons;
- sexual slavery;
- enforced sterilization;
- forced pregnancy;
- conscripting children under the age of 15.
Prosecution for war crimes requires the existence of an armed conflict and that the perpetrator was aware of the conflict (ICC, Elements of Crimes, § 8).
In the context of command responsibility, the ICC will use an "overall control test," which requires that the defendant have "a role in organizing, coordinating or planning the military actions of the military group, in addition to financing, training and equipping the group or providing operational support to it" (ICC, Lubanga, Confirmation of Charges § 211).