The Nuremberg Moment Closing In On Russian Leaders

On June 25, 2025, Ukrainian President Volodymyr Zelensky signed a bilateral agreement with the Council of Europe to create a Special Tribunal for the Crime of Aggression against Ukraine. This marks a major step toward holding Russia’s leadership accountable for launching the full-scale invasion in 2022. The Council of Europe, an international organization consisting of 46 nations, is dedicated to upholding human rights, democracy and the rule of law. Speaking at the Parliamentary Assembly of the Council of Europe (PACE), the parliamentary arm of the Council of Europe, President Zelensky thanked the assembly and underscored the importance of justice.

As President Zelensky recognized: “It was here in this Assembly that the first call for such a tribunal was made. The idea was born here, and now it’s gaining real support from partner countries in Europe and beyond. It will take strong political and legal co-operation to make sure every Russian war criminal faces justice, including Putin. This is the path we must walk – all the way to real charges and real verdicts.” He further added, “The aggressor must lose. We’re working on that. But justice matters too. It must work so that war criminals have nowhere to hide, not in Europe, not anywhere. And in a way that sets a legal principle – NO rewards for aggression.”

PACE President Theodoros Rousopoulos commented that: “For over 1,200 days and nights, the people of Ukraine have lived what I once called a thousand nightmares. And among those nightmares, one stands out as the most dangerous: that the world might become accustomed to this war. That a full-scale invasion of a sovereign state becomes normalized. That war crimes become invisible. But this Assembly – this Council – was created to stand precisely against such moral erosion.”

The new Tribunal will have a mandate to prosecute senior leaders for the crime of aggression – the decision to use armed force against another state – in violation of the UN Charter. Senior legal experts from a “core group” of around 40 states worked together with the Ukrainian authorities, the Council of Europe and the EU to draft the three legal instruments needed to establish the Special Tribunal.

The Special Tribunal aims to close a key legal gap in existing international accountability mechanisms – to address the crime that started it all – the crime of aggression. While many of the crimes perpetrated by Putin and his troops are already being investigated and prosecuted, whether by domestic or international tribunals, the crime of aggression is yet to be addressed with comprehensive responses. While, for example, the International Criminal Court (ICC) has powers to investigate any acts of genocide, war crimes and crimes against humanity committed on the territory of Ukraine, it cannot exercise its jurisdiction with regard to the crime of aggression against Ukraine. This is because the act of aggression is committed by Russia, a state that is not a party to the Rome Statute. One option would be for the U.N. Security Council to refer the situation to the ICC. However, such an attempt would have been blocked by Russia, a permanent member of the U.N. Security Council with a veto right. As such, States and experts have been looking into other options to ensure that the mother of all crimes in Ukraine – the crime of aggression – does not escape accountability.

The Special Tribunal will not start from scratch but will benefit from the work of the International Centre for the Prosecution of the Crime of Aggression Against Ukraine (ICPA) operating for two years now, securing evidence and facilitating the process of case building at an early stage.

The Special Tribunal will complement the efforts of the ICC by targeting high-level officials responsible for starting the war, such as Putin and his inner circle, and add to the many other avenues for justice and accountability already underway. The Special Tribunal must be welcomed as an important step to address the crime of aggression, which continues to fall through the cracks of international legal norms.