The ICC operates on the principle of complementarity, which means

that the ICC can exercise jurisdiction over a case only if the state with jurisdiction is unable or unwilling to prosecute the crimes. This principle ensures that the ICC does not replace national judicial systems but rather complements them. The ICC steps in when domestic authorities are unable or unwilling to act, thereby filling the gap in accountability for international crimes. This principle also encourages states to take responsibility for prosecuting international crimes themselves and provides a framework for collaboration between the ICC and national authorities.