In this interview, Professor Claus Kreß discusses the current state of the international legal order, the renewed significance of the crime of aggression, and the role of the International Criminal Court in a time of profound geopolitical tension.
The conversation begins with an assessment of the present crisis of the international legal order. Professor Kreß reflects on the pressures generated by the conduct of major powers, the challenges posed to the prohibition of the use of force, and the risk that certain authoritarian tendencies may reshape the future of international law. At the same time, he emphasizes the resilience of international law and the continued importance of international judicial institutions, particularly the International Court of Justice, in preserving a law-based international order.
The interview then turns to the crime of aggression. Professor Kreß explains why this crime has regained central importance within the broader architecture of international criminal law. He highlights the prohibition of the use of force as a cornerstone of the United Nations Charter and argues that the criminalization of aggression serves a crucial expressive and legal function: it affirms that the international community is not prepared to accept unlawful wars of aggression. In this context, he discusses the legacy of Nuremberg and Tokyo, the Kampala amendments to the Rome Statute, the jurisdictional limitations currently faced by the International Criminal Court, and the ongoing efforts to establish a Special Tribunal for the Crime of Aggression against Ukraine.
A central part of the conversation is devoted to the International Criminal Court and its institutional position within the international legal order. Drawing on the image of the Court as a “supranational island in an ocean of States,” Professor Kreß explains the tension between the Court’s ambitious mandate to protect fundamental values of the international community and its practical dependence on State cooperation. He examines the consequences of this dependence for the enforcement of arrest warrants, the collection of evidence, the surrender of accused persons, and the overall effectiveness of international criminal justice.
The interview also addresses the contemporary threats faced by the International Criminal Court, including failures of cooperation by States Parties, political resistance to the Court’s decisions, and coercive measures directed against the Court, its Prosecutor, and its judges. Professor Kreß stresses that the independence of the Court is essential to its legitimacy and that States Parties must be prepared to protect both the institution and its personnel against external pressure.
The conversation concludes with a reflection on the need to defend and strengthen international legal institutions in times of crisis. Professor Kreß underlines that moments of crisis also create opportunities for reform, renewed commitment, and cross-regional cooperation. He also points to the importance of future discussions on the relationship between the complementarity system of the International Criminal Court and Colombia’s transitional justice framework, particularly the Colombian Special Jurisdiction for Peace