Are there any limits to what crimes can be prosecuted?

The Prosecutor has jurisdiction only over crimes committed after 1 July 2002, when the Rome Statute entered into force. Equally important, the Office has jurisdiction only over crimes committed on the territory of a State Party to the ICC or by a State Party national unless a situation is referred to the Prosecutor by the United Nations Security Council. Finally, the Prosecutor can intervene only if the relevant national judicial authority is unable or unwilling to genuinely investigate and prosecute the alleged crimes. This is what is meant by the principle of complementarity in the Rome Statute whereby States have primary responsibility for preventing and punishing atrocities committed in their own territories and by their own nationals.