Prosecuting the Crime of Aggression: The Limits of International Law and the Case for a Special Tribunal on Ukraine.

This thesis examines the prosecution of the crime of aggression under international law, focusing on the Russian Federation’s aggression against Ukraine and on the proposal to establish a special tribunal. The analysis first reconstructs the historical evolution of the prohibition of war and the criminalization of aggression, from early attempts to regulate the use of force to the post-Second World War tribunals and the modern definition of the crime. Particular attention is devoted to the Rome Statute system, the Kampala Amendments, and the jurisdictional framework of the International Criminal Court, as the main permanent mechanism for the prosecution of international crimes. The thesis then applies this legal framework to the Russia–Ukraine conflict, examining the 2014 annexation of Crimea, the conflict in Donbas, and the 2022 full-scale invasion. It argues that Russia’s conduct amounts to a manifest violation of the United Nations Charter and therefore meets the legal threshold of the crime of aggression. At the same time, the thesis highlights the limits of the current international criminal justice system, especially the restrictions on the ICC’s jurisdiction over the crime of aggression in the Ukrainian situation and the impact of the Security Council veto. Against this background, the thesis assesses the establishment of a special tribunal for the crime of aggression against Ukraine. It explores its origins, legal rationale, political support, and feasibility, arguing that such a tribunal may offer a possible response to the existing accountability gap. While its creation raises legal and political challenges, it could contribute to individual accountability and strengthen the contemporary legal regime governing the prohibition of aggression.