Ukrainian President Volodymyr Zelenskyy has publicly thanked the Parliamentary Assembly of the Council of Europe (PACE) for its “real leadership” in confronting Russian aggression, following the formal signing of a new international tribunal dedicated to prosecuting the crime of aggression against Ukraine.
The agreement, which was signed on June 25th in Strasbourg by Council of Europe Secretary General Alain Berset and President Zelenskyy, marks the first formal step towards holding senior Russian leaders personally accountable for launching the full-scale invasion of Ukraine in February 2022. Unlike the International Criminal Court, which faces limitations in prosecuting the crime of aggression when the state involved is not a party to its statute, this tribunal is specifically tailored to address the invasion of Ukraine.
“It was here in this Assembly that the first call for such a tribunal was made,” Mr Zelenskyy told a packed chamber of European parliamentarians. “The idea was born here – and now it’s gaining real support from partner countries in Europe and beyond.”
“No Rewards for Aggression”
The Ukrainian president, whose wartime diplomacy has taken him across global capitals over the last three years, used the occasion to underscore that military success alone is not enough. “It will take strong political and legal co-operation to make sure every Russian war criminal faces justice – including Putin,” he said. “This is the path we must walk – all the way to real charges and real verdicts.”
Zelenskyy’s message was unambiguous: peace cannot come at the cost of principles. “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.”
The tribunal, which has been under development by a “core group” of roughly 40 countries in cooperation with Ukrainian authorities, the Council of Europe, and the European Union, will focus on the crime of aggression itself—the political and military decision to wage war in breach of the United Nations Charter.
An Assembly Steeped in Principle
President Zelenskyy’s address was warmly received by members of the Assembly, many of whom stood to applaud his words. PACE President Theodoros Rousopoulos introduced Zelenskyy with a reference to the Greek tragedian Aeschylus, declaring: “We must suffer, suffer into truth. This is the daily reality of Ukraine.”
“For over 1,200 days and nights, the people of Ukraine have lived what I once called a thousand nightmares,” Rousopoulos said, visibly moved. “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 normalised. That war crimes become invisible.”
He went on to affirm the Council of Europe’s founding purpose: to defend the rule of law, democracy and human rights—principles now under open assault by the Kremlin’s war machine.
“This Assembly – this Council – was created to stand precisely against such moral erosion,” he said.
Breaking New Ground
The proposed tribunal represents a legal innovation. While the International Criminal Court in The Hague has issued an arrest warrant for Russian President Vladimir Putin over the abduction of Ukrainian children, its jurisdiction does not currently extend to the crime of aggression in this case, as Russia is not a party to the Rome Statute.
This legal gap, many international lawyers argue, risks allowing senior Russian leaders to escape prosecution for the most fundamental crime of all: launching an unprovoked war of conquest. The new tribunal aims to plug that gap.
Designed to be international but rooted in Ukrainian law, the tribunal will allow for the prosecution of senior political and military leaders who orchestrated the invasion. Legal observers note that the architecture of the tribunal is reminiscent of the Nuremberg trials in the aftermath of the Second World War—deliberate, and not without symbolism.
Europe as Custodian of Law
Mr Zelenskyy’s visit to Strasbourg was more than symbolic—it was strategic. By embracing the Council of Europe, a body distinct from the European Union and focused squarely on human rights and democracy, the Ukrainian president is reinforcing a broader message: that Ukraine’s struggle is not just national, but civilisational.
This was echoed in his remarks to the Assembly. “We are defending not only our borders and our people,” he said, “but the very idea that law must prevail over brute force.”
While Russia continues to target civilian infrastructure across Ukraine and intensifies its mobilisation efforts, European institutions are responding not just with weapons and aid, but with justice mechanisms. The creation of the tribunal is intended to show that those responsible for this war will face consequences—not merely in the court of history, but in courts of law.
A Long Road Ahead
Of course, the path from agreement to indictment is long and fraught. International tribunals move slowly, and geopolitical realities mean that any chance of securing custody of high-ranking Russian officials in the near term remains slim.
But the point, Mr Zelenskyy insisted, is not just to punish—it is to establish a principle. That wars of aggression are not just wrong—they are criminal. And that Europe, for all its flaws and divisions, can still serve as the custodian of that principle.
Today in Strasbourg, beneath the flags of 46 member states, that message rang clearly: justice will not wait for peace to begin. It must accompany it—and, in part, deliver it.
Main Image: Council of Europe.
