In earlier experiments with international criminal justice, a tribunal was established and its prosecutor assigned to identify deserving cases. There was no need to ‘trigger’ the jurisdiction, because the target of prosecution was already defined by the enabling legislation. Thus, the International Military Tribunal at Nuremberg was assigned to prosecute ‘the major war criminals of the European Axis’. It was left to the prosecutor to determine who those individuals might be. Similarly, the prosecutors of the United Nations international criminal tribunals for the former Yugoslavia, Rwanda and Sierra Leone were given essentially free reign to identify their targets. But this was not terribly difficult, given that the exercise of prosecutorial discretion was so carefully circumscribed by the jurisdiction of the Court itself. The members of the Security Council who created the International Criminal Tribunal for the former Yugoslavia did not feel particularly threatened by the exercise of prosecutorial discretion because they had created an institution whose jurisdiction was limited to crimes committed on the territory of the former Yugoslavia. In effect, the resolution itself that established the Tribunal was also its ‘trigger’.

The situation is quite different with respect to the International Criminal Court. The Court's focus of prosecution is not pre-determined, as has been the case with the earlier ad hoc institutions. Determination of the International Criminal Court's ‘trigger’ of jurisdiction proved to be highly contentious during the negotiations.