EU Joins Special Tribunal to Prosecute Russian Aggression in Ukraine
The European Commission, acting on behalf of the European Union, joined on 15 May 2026 the Enlarged Partial Agreement of the Special Tribunal for the Crime of Aggression against Ukraine — the foundational document that sets out the institutional, financial and administrative modalities for what may become one of the most ambitious accountability mechanisms of the post-1945 era.
Following the EU’s accession, participating states and international organisations will be able to ratify the Convention that will formally establish the Tribunal. Once operational, it will have jurisdiction to investigate and prosecute senior Russian political and military leaders for the crime of aggression — the original international crime under which the 1945 Nuremberg trials proceeded.
“A significant step forward”
Michael McGrath, the Commissioner for Democracy, Justice, the Rule of Law and Consumer Protection, framed the decision in unambiguous terms: “Today marks a significant step forward in delivering justice for the people of Ukraine. A true, just and lasting peace cannot exist without justice and accountability.”
The founding legal texts of the Tribunal were politically endorsed by an international coalition of states and international organisations on 9 May 2025 — symbolic date in itself, marking 80 years since the surrender of Nazi Germany. The intervening twelve months have been spent translating that political endorsement into ratifiable instruments.
Why the Special Tribunal matters
Existing international tribunals — primarily the International Criminal Court (ICC) in The Hague — can prosecute war crimes, crimes against humanity, and genocide committed on Ukrainian territory. But the ICC cannot, in current circumstances, prosecute the crime of aggression committed by Russian leaders against Ukraine, because neither Russia nor Ukraine has accepted the Court’s jurisdiction over that specific offence in the relevant configuration.
This jurisdictional gap is what the Special Tribunal is designed to close. As the Commission noted in its accompanying communication, “the Special Tribunal and the Claims Commission will be the fundamental international bodies ensuring full accountability for the international crimes, and compensation for damages, committed in Ukraine.” The EU played a leading role throughout the drafting of the founding legal texts.
What comes next
The Tribunal will be seated within the Council of Europe framework, with the Enlarged Partial Agreement open to non-Council-of-Europe states. Ratifications are now expected to proceed in parallel across European capitals through the summer. The first practical questions — appointment of prosecutors and judges, evidentiary protocols, the relationship with the ICC and with national jurisdictions — will dominate the institutional agenda over the coming year.
Ukraine has consistently championed the Tribunal as a complement, not a substitute, to existing accountability mechanisms. For Brussels, the project carries an additional strategic dimension: it positions the European Union not only as the principal financial and military backer of Ukraine’s defence, but as the institutional anchor of post-war accountability — a role likely to outlast any specific ceasefire or peace agreement.
