Deterring War Crimes

The International Criminal Court (ICC) was created by the Rome Statute to prosecute and adjudicate international crimes, such as war crimes and crimes against humanity. The ICC applies a jurisdictional rule known as the rule of complementarity. Under this rule, the ICC may not prosecute crimes that are investigated or prosecuted by a state. The ICC could have adopted a rule of primacy — such as that adopted by the International Criminal Tribunal for the Former Yugoslavia (ICTY) — that would allow it to prosecute cases even if they were investigated or prosecuted by a state. This paper explores the conditions under which complementarity better deters officers from committing war crimes than does primacy. It concludes that the jurisdictional rule that better deters officers depends on the probability of prosecution by the ICC that officers face. Complementarity deters more officers when the probability of prosecution is low, as it is now. But if the probability of prosecution increases significantly, then better deterrence can be achieved by shifting to primacy.