An overview of the ICC complementarity regime

One of the main objectives of the Rome Treaty establishing the permanent International Criminal Court is to advance the unification of international criminal law. Whilst it may be contended that this body of law is acquiring a great degree of specificity and uniformity in content through the ICC Statute, both its development and importantly its scope are fundamentally reliant on its interpretation and application at national level; it is here that the enforcement of complementarity measures are fragmented. In this piece, the validation of the ICC surrender and deferral rationale and mechanisms are analysed against the ICC Statute’s procedural safeguards vis-à-vis national ones. Problems of ICC Treaty implementation go beyond the mere Treaty language; notwithstanding the principle of pacta sunt servanda, these lie in the contradiction between the legal principle in question (complementarity) and interpretation and reconciliation with constitutionalism. Whereas the ICC Treaty arguably erodes national sovereignty, varying implementation methods will define, broaden or limit the scope and the jurisdictional reach of the ICC. This may be illustrated for instance, from observing the extent to which traditional extradition defences have survived the ICC surrender model, regional amnesties and ICC Article 98 non-surrender agreements. The Court’s jurisdiction may not be triggered automatically nor be imposed on states through the mere accession to the Rome Treaty. The fragmented application of the ICC Statute, which may be evidenced also through the multiplicity of Rome Treaty implementation methods, reflects the jurisdictionally imbalanced ICC legal regime