The Special Tribunal for the Crime of Aggression against Ukraine: How a Demand for Justice Became an International Decision

Some decisions do not appear overnight.

They are born out of pain, persistence, hundreds of meetings, statements, letters, legal texts, diplomatic consultations, and political decisions.

The establishment of the Special Tribunal for the Crime of Aggression against Ukraine is exactly such a process.

It is an answer to the central question of this war: who made the decision to attack Ukraine, destroy cities, kill thousands of people, and force millions to leave their homes?

War crimes, crimes against humanity, and genocide must be investigated — and they already are. But the crime of aggression — the very decision to start a war — requires a separate mechanism of accountability.

That is why, from the first months of the full-scale invasion, Ukraine insisted that a Special Tribunal must be established.

And the Council of Europe became one of the key platforms where this idea moved from a political call to a concrete international legal mechanism.

This path began in the very first months after the full-scale invasion.

In March 2022, the Russian Federation was expelled from the Council of Europe. This was the first clear signal: an aggressor state cannot remain part of an organisation founded on human rights, democracy, and the rule of law.

Already in April 2022, the Parliamentary Assembly of the Council of Europe became one of the first international institutions to call for the creation of a special international tribunal for the crime of aggression against Ukraine. For Ukraine, this became an important political point of support.

Since then, the Permanent Representation of Ukraine to the Council of Europe has worked systematically to ensure that this idea did not remain merely a call.

In 2022–2023, the Permanent Representation consistently brought the issue of the Special Tribunal onto the agenda in Strasbourg: through meetings of the Committee of Ministers of the Council of Europe, contacts with the presidencies of the Committee of Ministers, consultations with member states, work with the Parliamentary Assembly, and special events dedicated to holding Russia accountable.

It was during this period that a broader architecture of justice began to take shape within the Council of Europe: the Special Tribunal and the international compensation mechanism for damage caused by the Russian Federation’s aggression against Ukraine, including the Register of Damage and the Compensation Commission.

On 16–17 May 2023, at the Council of Europe Summit in Reykjavík, the Register of Damage Caused by the Aggression of the Russian Federation against Ukraine was established. This was the first practical element of the international compensation mechanism. For the Permanent Representation of Ukraine to the Council of Europe, this stage also meant continuing efforts to keep accountability for the crime of aggression closely linked to the issue of compensation — as an inseparable part of a just peace.

In 2024, the process moved from political support to legal preparation. The Council of Europe joined the work on the future founding documents of the Special Tribunal, while the Permanent Representation in Strasbourg ensured constant coordination with Council of Europe institutions, member states, and Ukrainian authorities.

In March 2025, the coalition of states working on the establishment of the Special Tribunal completed technical work on the key legal instruments. And already in May 2025, Ukraine officially addressed the Council of Europe with a proposal to launch the process of establishing the Tribunal through an agreement between Ukraine and the Council of Europe.

The Permanent Representation then held consultations with the leadership of the Council of Europe, the presidency of the Committee of Ministers, key partner states, and the Secretariat. This was about what often remains behind the scenes: agreeing on procedures, texts, decisions, mandates, signing formats, and the political support of member states.

On 24 June 2025, the Committee of Ministers of the Council of Europe authorised the Secretary General of the Council of Europe to sign the Agreement on the establishment of the Special Tribunal.

On 25 June 2025, in Strasbourg, Ukraine and the Council of Europe signed the Agreement on the establishment of the Special Tribunal for the Crime of Aggression against Ukraine.

This was an important moment — but not the final one. After the signing of the Agreement, the most responsible stage began in autumn 2025: the practical launch of the Tribunal.

To this end, the Permanent Representation of Ukraine to the Council of Europe, together with colleagues from the Ministry of Foreign Affairs, continued its work in the Committee of Ministers and within the GT-TRIBUNAL working group established at the Council of Europe. There, states considered the work of the International Core Group, prepared key documents of the future Special Tribunal for formal adoption, and discussed numerous technical issues.

At the same time, work continued on establishing the Claims Commission for Ukraine as the second element of the international compensation mechanism for damage caused by the Russian Federation’s aggression against Ukraine. On 16 December 2025, the Council of Europe Convention establishing the Claims Commission for Ukraine was opened for signature.

In parallel, at the end of 2025, the decisive stage of work on launching the Special Tribunal unfolded. The Permanent Representation of Ukraine to the Council of Europe, together with colleagues from the Ministry of Foreign Affairs, worked within GT-TRIBUNAL on the text of the Enlarged Partial Agreement on the Steering Committee of the Special Tribunal. By the end of 2025, this work had been completed. Behind it stood numerous meetings, consultations with partners, discussions with the Council of Europe Secretariat, and constant coordination with Kyiv.

After the text of the Enlarged Partial Agreement was finalised, the key issue became its launch.

At this stage, the Permanent Representation of Ukraine to the Council of Europe prepared its own input for the draft decision of the Committee of Ministers that was to accompany the launch of the Agreement.

It was precisely the approaches developed by the Permanent Representation and agreed with partners that helped change the dynamics of the process. The discussion moved from waiting for additional conditions to agreeing on a concrete political decision. As a result, already in March 2026, states agreed on the relevant draft decision based on our proposals, paving the way for the launch of the Enlarged Partial Agreement at the 135th Ministerial Session of the Committee of Ministers of the Council of Europe in Chișinău.

On 15 May 2026, the Enlarged Partial Agreement on the Steering Committee of the Special Tribunal was adopted by 36 states and the European Union. This marked a major step from a political idea to a real mechanism of justice.

What matters in this chronology is not only each date. What matters is the daily work between them: statements, consultations, explanations, the search for allies, the preparation of documents, responses to states’ concerns, coordination with Kyiv, and the constant effort to keep the Council of Europe’s attention focused on the Special Tribunal.

This is how Ukraine’s diplomatic demand — to ensure punishment for the crime of aggression — gradually became an international legal process.

For the ordinary reader, international law often seems complex and distant. But at the heart of this process lies something very simple and clear: no one has the right to start a war against another state with impunity.

The crime of aggression is not an abstract legal formula. It is the decision after which missiles began flying into Ukraine. It is the decision after which Ukrainian families lost their homes, loved ones, security, and normal lives. It is the decision that opened the door to thousands of other crimes.

That is why the Special Tribunal is necessary for Ukraine.

It must provide an answer to the crime from which the full-scale war began.

It must become a mechanism of accountability for those who made and implemented the decision to commit aggression.

It must show that international law is not only texts and declarations, but also an instrument for protecting people, states, and peace.

The Permanent Representation of Ukraine to the Council of Europe has been and remains part of this work in Strasbourg.

We worked to ensure that the issue of the Special Tribunal was heard in the Committee of Ministers of the Council of Europe, in the Parliamentary Assembly, in the Congress of Local and Regional Authorities, in working groups, in informal consultations, in contacts with member states, and in daily interaction with Council of Europe institutions.

This work is often not public. It does not always make the news. But it is precisely this work that international decisions are built from.

It is work in which it is important not to allow the world to grow tired of Ukraine. Not to allow justice to be replaced by political convenience. Not to allow the crime of aggression to remain unpunished simply because the path to accountability is difficult.

For Ukraine, this Tribunal is not a symbol. It is a path to justice for the state and for its people.

It is an investment in a future in which aggression will not be the norm in international relations.

It is a reminder that peace without accountability cannot be just or lasting.

The Permanent Representation of Ukraine to the Council of Europe sincerely thanks everyone who has contributed to this process: Ukrainian state institutions, the Council of Europe, its Committee of Ministers, the Parliamentary Assembly and the Secretariat, member states and partners, legal teams, the diplomatic corps, experts, representatives of civil society, and everyone who has consistently worked — and continues to work — for justice for Ukraine.

Justice does not come by itself.

It is fought for.
It is built.
It is defended.

And Ukraine, together with its partners, is doing everything to ensure that the crime of aggression against our state does not go unpunished.