On 24 February 2022, Russian troops crossed Ukraine’s borders. While the effects were immediate, the legal consequences were not. The International Criminal Court (ICC) began investigating war crimes and crimes against humanity, but the most important leadership-charge remained untouchable: the crime of aggression.

The crime of aggression is often referred to as the “supreme international crime”. Yet in this case, the prosecuting court in international criminal law cannot act, because Russia is not a party to the Rome Statute. The only alternative would be a referral by the United Nations Security Council (UNSC) under Chapter VII of the Charter, but Russia, as its permanent member, would without doubt make use of its veto power. In effect, the ICC lacks jurisdiction over this crime in Ukraine. As many scholars have put it, we face a jurisdictional gap. Out of this gap, a political and legal novelty project was born: The Special Tribunal for the Crime of Aggression against Ukraine.

A Tribunal Born in Lviv and Strasbourg

On 9 May 2025, a meeting between foreign ministers in Lviv concluded with the announcement that the legal groundwork for the special tribunal was completed. Shortly after, on 24 June 2025, Ukraine and the Council of Europe signed the agreement establishing the tribunal. According to its Statute, the tribunal has jurisdiction over persons who bear the greatest responsibility for the crime of aggression against Ukraine, derived from Ukraine’s territorial jurisdiction over the crimes committed against it. It will apply the established Statute, international law, and, subsidiarily, Ukrainian law. Most importantly, official capacity “shall not relieve a person of criminal responsibility”. In simple terms: the tribunal aims to prosecute the so-called “Troika”, the top political and military leadership. But can it really do what the ICC cannot?

The Case For: Closing the Accountability Gap

In light of the existing jurisdictional gap, supporters amongst scholars argue that remaining passive would be worse. Carrie McDougall calls a special tribunal “the best available option” and applies pragmatic reasoning. The ICC’s jurisdictional regime on aggression is the result of painful compromises, tracing back to the Kampala Amendments to the Rome Statute in 2010. Reform is unlikely and would require near-universal support. Waiting for a perfect solution means accepting impunity.

Anne Peters and Robert Stendel take the argument even further. They claim that a tribunal based on an agreement between Ukraine and the Council of Europe is a legitimate strategy. For them, the regional anchoring avoids accusations of double standards, as the Russian aggression directly concerns the European peace order. If Europe cannot respond regionally and legally to a war on its own continent, what remains of its commitment to peace? Supporters also stress symbolism. Aggression is the leadership crime and without prosecuting it, we risk telling the world that those who decide on wars enjoy special protection. A tribunal would reaffirm that launching a war, a manifest violation of the prohibition of the use of force under international law, is not only unlawful but criminal.

There is also a doctrinal point to be made. Immunities that protect sitting heads of state before foreign national courts do not automatically apply before international courts and tribunals. If the new body qualifies as a genuine international tribunal, it may pierce the shield that would otherwise protect high-ranking officials. The Statute reflects this ambition by excluding official capacity as a defence.

In summary, the supporters’ message is clear: law must adapt when politics blocks justice.

The Case Against: Legitimacy, Selectivity, and Realism

Critics are not advocating on Russia’s behalf, but they are questioning the legal and political methods.

Kevin Jon Heller has referred to the creation of a special tribunal as a “bad idea”. His concerns are practical and principled. How will the tribunal arrest and surrender suspects? He argues that most evidence of aggression lies in Moscow, not on the battlefield. Without regime change in Russia, arrests are unlikely. A court without defendants risks becoming a symbolic institution rather than a functioning one.

Kai Ambos raises a different alarm. From a non-Eurocentric perspective, a tribunal focused on Russia may look selective. Why is there one for Ukraine and not for the crimes Iraq endured in 2003? Why now? If international criminal law appears to move only when Western interests are affected, its credibility takes a hit. Ambos also questions whether circumventing the ICC’s carefully negotiated aggression regime sets a dangerous precedent. Instead of creating parallel structures and risking fragmentation of international criminal law, should states not reform the ICC as such?

There are also doubts about the tribunal’s legitimacy being voiced. Can a tribunal created without UNSC backing truly override personal immunities of sitting leaders? The core argument is that only a fully international body, ideally endorsed by the United Nations General Assembly, could convincingly claim such authority.

A regionally anchored tribunal might struggle to assert the same status.Finally, there is the peace-versus-justice dilemma. Some fear that indicting top leaders may complicate diplomatic efforts. Even if peace talks seem distant, law cannot operate in a vacuum.

Between Idealism and Perfection

The debate reveals a deeper tension in international law. We want universality, but we often act regionally. We want consistency, but we live in a world shaped by a dominance of power politics.

From a legal perspective, the most interesting question is whether the tribunal qualifies as an “international tribunal”. It has international judges, applies international law, and is established through an agreement with the Council of Europe as an international organisation. These elements strengthen its claim. But the qualification as such has direct implications on its ability to exercise jurisdiction, especially in regard to overriding immunities. It is the recognition and cooperation by states that will ultimately decide its effectiveness.

From a political perspective, the project is a test for Europe. If the Council of Europe can create and sustain such a court, it may signal that regional organisations can play a strong role in international criminal justice. If it fails, critics will say they warned us.

A Necessary Risk?

Is the Special Tribunal perfect? No. Is it politically charged? Yes. But international criminal law has never developed in calm waters, it evolves through crises. The choice is not between an ideal global court and a flawed regional one, but between an imperfect attempt at establishing accountability and a silent acceptance of the status quo. The Special Tribunal is more than a court. It is a statement. Whether it becomes a milestone or a symbolic effort depends not on the judges and lawyers, but on the states’ willingness to cooperate. If the crime of aggression is the “supreme crime”, then ignoring it would be the supreme failure.

Written by Ramona Reither, Edited by Aleksandra Drozd.

Photo Credit: Jaiju Jacob (2021, January) on Pexels.