The advent of the ICC as a permanent international criminal court to try and punish alleged perpetrators of the most serious crimes of concern to the international community as a whole is a crucial step forward in the architecture of international criminal justice. Nevertheless, as significant as the ICC is in the world today, we must remember that it is but one element in the broader global effort of eliminating impunity for international crimes. The role of the ICC in the framework of international criminal justice has accurately been referred to as that of a ‘court of last resort’. The permanence of the ICC ensures that there will always be a forum where perpetrators of international crimes may be held accountable; but this does not mean that all such crimes can or will be prosecuted before the ICC. The Rome Statute is built upon the premise that states have the primary obligation to take measures at the national level to ensure that the most serious crimes of concern to the international community as a whole do not go unpunished by investigating and prosecuting such crimes. Thus, national criminal jurisdictions are expected to take the lead in the fight against impunity.

The ‘principle of complementarity’ is one of the pillars of the system of international criminal justice created by the Rome Statute. While the principle of complementarity in its narrow sense refers to the admissibility of cases before the ICC, it has many other dimensions which are only beginning to be explored, such as ‘positive’ or ‘proactive’ complementarity. The present volume covers many of the different aspects of this fundamental principle. The authors offer insights into the theory and practice of complementarity, and the various contributions in this volume should lead to a better understanding of the principle of complementarity and its impact on the development of international justice. It is my hope that they will be a source of inspiration and provide invaluable insight for judges, practitioners, academics and researchers alike.

In 1945, the peoples of the United Nations announced their determination to save succeeding generations from the scourge of war. To this end, they committed themselves to unite their strength to maintain international peace and security. The nations resolved to build an international society based on friendly relations between each other, rather than war. The United Nations was born. Half a century later, 120 states met at the Rome Conference. Recognizing that millions of children, women and men continue to be the victims of unimaginable and horrific crimes which threaten the peace and security of the world, they decided to establish the first permanent international criminal court. By so doing, they endorsed the fundamental principle which had been steadily emerging and consolidating over the preceding decades: the principle that justice is a fundamental component in any peace process.

The International Criminal Court is the very crystallization of our global culture of accountability. It enshrines the conviction, shared by the overwhelming majority of the members of the international community, that no sustainable peace can ever be built on foundations of impunity. The time has passed when we talk of peace versus justice and we now accept that justice is a necessary component of peace. The two are inseparable: they go together hand in hand. In this, the United Nations and the ICC share a common goal. At the same time, as a permanent institution, the ICC has the advantage of having a continuing deterrent effect on decision-makers at the highest level. Indeed, the system put in place by the Rome Statute is designed to reach those who bear the ultimate responsibility for the most serious crimes. As a court of last resort, the ICC provides a permanent and standing complement to national criminal accountability mechanisms. This complementarity principle is a cornerstone of the ICC regime. The fight against impunity rests upon the complementary efforts of domestic jurisdictions and the ICC. For this reason, the United Nations was a strong advocate for the establishment of an international criminal court since the early 1990s. It also played a key role in the Rome Conference and in ensuring its success. Since the Rome Statute entered into force and the Court came into being, the United Nations and the Court have built a firm relationship of cooperation which grows stronger year by year.

Abstract

This chapter examines the genesis of the concept of complementarity. It argues that, unlike the common perception among many scholars, complementarity is not a novel concept attributed to the sole work of the International Law Commission or any subsequent effort. Rather, the concept existed a long time before the International Law Commission was seized of its mandate to prepare a draft statute establishing an international criminal court. The parameters and the legal conditions that organized the concept's operation developed over a period of seventy-nine years starting from 1919 and ending with the adoption of the Rome Statute in 1998. The elaboration of these legal criteria throughout this lengthy period led to the emergence of different models of complementarity, one of which is the 1998 Rome Statute's model. Every model was introduced during a certain period for quite different, but often overlapping philosophical and legal reasons. The common premise that underlined these complementarity models was that, irrespective of the reasons, an international criminal jurisdiction may do that which the national criminal jurisdiction was not in a position to do.

‘Complementarity’ is probably the concept that best describes the nature of the International Criminal Court. However, as usually happens with fundamental concepts, its meaning is open to interpretations and the full range of its theoretical and operational implications is still unclear.

It would not be an over-statement to affirm that the early agreement on a complementarity regime was what made the Court possible. By the time delegations gathered in Rome, complementarity was the only major issue that we had largely managed to resolve -- not because it was easy, but probably because it was such a key feature of the future institution that articulating an acceptable compromise on complementarity appeared as a precondition to making progress in the rest of the negotiating process.

Acomplementarity systemwas indeed essential to defining the relationship between the Court and national states and to determining the limits of their respective spheres of action. Internationalism versus national sovereignty was the inevitable tension underlying the discussions but an abstract debate was pragmatically avoided and delegations were able to bridge their differences by focusing on the practical implications of the principle of complementarity for the activities of the Court.

The concept of complementarity was not new and the main features of the regime eventually adopted for the International Criminal Court were already contained in the 1994 draft statute prepared by the International Law Commission. This draft included the idea of concurrent jurisdiction between international and national jurisdictions but left out the principle of primacy of international jurisdiction that had been granted by the Security Council to the ad hoc tribunals for the former Yugoslavia and Rwanda only a few years before.