The main responsibility for prosecuting the crime of genocide, crimes against humanity and war crimes lies with States. This obligation of States to investigate and prosecute core international crimes has evolved over the last two centuries, with, inter alia, the Saint Petersburg Declaration of 1868, the Hague Conventions of 1899 and 1907, the Treaty of Versailles of 1919, the Charters of the Nuremberg and Tokyo Military Tribunals of 1945 and 1946, the Genocide Convention of 1948, as well as the Geneva Conventions of 1949 and their Additional Protocol I and II of 1977. The following sources of international law permit, and at times obligate, national authorities to identify, investigate and prosecute or extradite those responsible for the commission of core international crimes, regardless of where those crimes were committed and irrespective of the nationality of the perpetrator or the victim:
- Convention on the Prevention and Punishment of the Crime of Genocide of 1948 (Art. 1, 5 and 6);
- four Geneva Conventions of 1949 (GC I, Art. 49; GC II, Art. 50; GC III, Art. 129; GC IV, Art. 146) and the three Additional Protocols (AP I, Art. 85);
- Hague Convention for the Protection of Cultural Property in the Event of Armed Conflict of 1954 (Art. 28) and its Second Protocol (Art. 17(1));
- International Convention for the Suppression and Punishment of Apartheid of 1976 (Art. 4);
- Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment of 1984 (Art. 5(2) and 7(1));
- Rome Statute of the ICC of 1998 (Preamble, Recitals 4, 6 and 10 and Art. 1);
- International Convention for the Protection of all Persons from Enforced Disappearances of 2006 (Art. 3, 4, 6 and 9(2)); and
- customary international law.
Many of the obligations stemming from these international treaties and customary law were solidified in the Rome Statute of the ICC, through which State Parties reiterated the obligation to investigate and prosecute perpetrators of core international crimes. However, the ICC’s jurisdiction is restricted to crimes committed by a national of a State Party in the territory of a State Party, as well as to cases that have been specifically referred to the ICC by the United Nations Security Council, or where the State Party has specifically accepted the exercise of jurisdiction by the ICC. In addition, temporal limitations apply as the ICC’s jurisdiction is restricted to crimes that were committed after 1 July 2002. Moreover, the principle of complementarity means that the ICC only assumes jurisdiction in cases where States are unable or unwilling to do so. Accordingly, the ICC has or assumes jurisdiction in a very limited number of cases, therefore, the main responsibility to seek, investigate and prosecute those responsible for the commission of core international crimes lies with States.
Despite the general perception that core international crimes occur far away, experience has shown that these crimes, their perpetrators and their assets, their victims and witnesses are linked with EU Member States. The successful outcome of the investigations and prosecutions is dependent on close cooperation between the authorities involved as well as between Member States. EU Member States have a central role in the development of international criminal law, host many international tribunals and offer their full support; in the fight against impunity, this involves assisting national authorities in the prosecution and investigation of the crime of genocide, crimes against humanity and war crimes.