Eichmann, Pinochet, Barbie, Touvier, Rios Montt, Fujimori, Scilingo, Munyaneza, and Simbikangwa: a few among the thousands that have been processed, in the spotlight or below the radar, through national courts for the commission of atrocity crimes. The role of national jurisdictions in the fight against impunity for international crimes is the object of this chapter.

One of the justifications for the creation of international criminal institutions is the traditional failure of States where the crimes occurred, or of which the perpetrator is a national, to undertake investigations and prosecutions in respect of such crimes. The same rationale explains the development of the principle of universal jurisdiction. Universal jurisdiction is indeed based on the notion that some crimes – including genocide, crimes against humanity, war crimes, enforced disappearances, and torture – are of such exceptional gravity that they affect the fundamental interests of the international community as a whole. Every member of the international community therefore has a right – or an obligation, as we shall see – to ensure that these crimes do not go unpunished.

Interestingly, despite this fundamental rationale for the existence of international courts, the International Criminal Court has not followed the model of the ad hoc tribunals for the former Yugoslavia and Rwanda, based on the primacy of the international jurisdictions over national jurisdictions. The Court is ‘complementary to national jurisdictions’ and its Statute further affirms in the Preamble that it is ‘the duty of every State to exercise its criminal jurisdiction over those responsible for international crimes’ and that ‘the most serious crimes of concern to the international community as a whole must not go unpunished and that their effective prosecution must be ensured by taking measures at the national level and by enhancing international cooperation’. The Assembly of States Parties reaffirms this commitment at every meeting.

The International Criminal Court is thus based on the hope that classical assumptions to the effect that the post-conflict domestic dynamic prevents war crimes trials can be reversed. It is also based arguably on the idea that it forms part of a system of accountability for core international crimes, composed of a web of national jurisdictions able and willing to investigate and prosecute such crimes wherever they were committed, with the international institution ready to act to close the impunity gap where no State can or does so genuinely.