Legal Definitions - complementarity

The principle of complementarity is the idea that national courts have the primary responsibility to investigate and prosecute international crimes. The International Criminal Court (ICC) only steps in when a state is unable or unwilling to do so.

For example, if a war crime is committed in a country, the national court of that country should investigate and prosecute the crime. However, if the national court is unable or unwilling to do so, the ICC can step in and take over the case.

The principle of complementarity is important because it ensures that international crimes are addressed and that justice is served. It also respects the sovereignty of states and their ability to handle their own legal matters.