LONDON — In seeking justice and accountability for alleged war crimes committed by Russia in Ukraine, Karim Khan, the prosecutor for the International Criminal Court, urged United Nations member states to stay focused on “the suffering of humanity” and to “cling to the law.”

“We can’t be complacent and think peace, prosperity and economic advancement is the inevitable birthright of every child and every country . . . we can do better for victims around the world who crave the shelter of the law,” Khan said in his opening remarks at a justice ministers’ fund-raising conference held in London on March 20.

Although on its surface, the conference projected an image of international unity for justice in Ukraine and accountability for Russia — notions that Khan and President Volodymyr Zelensky of Ukraine agree on — simmering tensions between the two and among others reflect that the best way to achieve such goals is not a straight and narrow path.

Co-hosted by Britain’s Deputy Prime Minister Dominic Raab and Dilan Yesilgoz-Zegerius, the minister of justice and security for the Netherlands, and attended by more than 40 justice ministers worldwide, the conference generated nearly $5 million to support the continuing investigations by the court, or ICC, for alleged war crimes committed in Ukraine. The court also announced that it was opening a field office in Ukraine.

President Zelensky addressed the group by pre-recorded video. Beyond the collective West, those attending included government ministers from Ghana, Guatemala, Japan and South Korea. Zelensky acknowledged Khan’s efforts and the ICC for backing Ukraine in its “battle for justice,” but strongly emphasized the importance of supplementing “the work of the ICC with the establishment of a special tribunal for the Russian crime of aggression in Ukraine.” It is an ambition that Zelensky has been promoting for many months and one that Khan has adamantly rebuked, arguing that it would dilute the ICC’s power and fragment the pursuit of justice for Ukraine.

Khan did not mention the tribunal in his remarks on Monday, signaling that Ukraine’s preferred path to full equity for the war-battered nation continues to be a rocky ride for Kyiv, amid Russia’s murderous destruction.

Denys Maliuska, Ukraine’s minister of justice, and Andriy Kostin, its prosecutor general, attended the conference. In his remarks, Kostin called on countries to not allow the crime of aggression to go unpunished. “Yes, the International Criminal Court might be jurisdictionally constrained in relation to these crimes . . . however [it] should not stop us from striving to attain comprehensive justice,” he said. “In this regard, I call upon you to support the idea of the establishment of the international tribunal for the investigation and prosecution of the crimes of aggression.”

Indeed, a working group of 33 countries, including Ukraine, is meeting on March 21 and 22 in Strasbourg, France, to forge ahead on setting up a special tribunal to prosecute Russian officials for the crime of aggression.

Considered a “leadership crime” by the international justice community, the crime of aggression is considered to be the mother of all other war crimes, including crimes against humanity and genocide. However, the ICC cannot charge Russian leaders — including President Vladimir Putin — with the crime of aggression because Moscow is not a member of the court and its jurisdiction is limited to state parties that have ratified the Rome Statute, the ICC’s founding treaty. Currently, 123 countries have ratified the statute. The United States is not a party, either, which further complicates Ukraine’s mission to create a special tribunal for the crime of aggression, as the US does not want to set a precedent where one of its own leaders could be prosecuted for similar offenses.

However, on March 17, just three days before the 20th anniversary of the US invasion of Iraq, a conflict that some experts find comparable with Russia’s illegal invasion of Ukraine, the court issued warrants for the arrest of Putin and Maria Lvova-Belova, his children’s rights commissioner, for alleged war crimes. These include the unlawful deportation and transfer of Ukrainian children to Russia from occupied territories in Ukraine since the start of the full invasion in February 2022. The warrants are the first the court has ever issued for a head of state of a permanent member of the UN Security Council.

The action occurs as Russia is scheduled to lead the Council as rotating president in April. Calls for Russia to be legally ousted from the body are being made from many corners of the world, especially by Ukraine’s government, as Russia takes the presidency soon. But how Russia could be kicked out is questionable, given the constraints of the UN Charter and the country’s veto right.

On Feb. 28, 2022, four days after Russia invaded Ukraine, Khan opened an investigation to probe “alleged war crimes and crimes against humanity” being committed “by any party to the conflict on any part of the territory of Ukraine.” The warrant issued for Putin (and for Lvova-Belova) is a result of the evidence gathered by the ICC’s continuing probes so far.

In London, Khan described the warrant as a “very sad” and  “somber occasion” and not a moment for “triumphalism.”

By contrast, Vassily Nebenzia, Russia’s UN envoy, referred on March 17 to the warrant as “illegitimate, invalid and null and void” and called the court an “incompetent, international body which has once again demonstrated how damaging and invalid it is.” Nebenzia made his remarks at a UN Security Council meeting on the ever-deteriorating humanitarian crisis in Ukraine. The deputy chair of Russia’s own Security Council tweeted about the warrant: “No need to explain WHERE this paper should be used” followed by an image of toilet paper.

Meanwhile, in her remarks at the same UN Security Council meeting, US Ambassador Linda Thomas-Greenfield did not comment on the warrant. President Joe Biden called it “justified.”

For months, Sergiy Kyslytsya, Ukraine’s envoy to the UN, alongside Christian Wenaweser, Liechtenstein’s envoy, have been lobbying other member states across all regions to support a General Assembly draft resolution that would trigger the creation of a special tribunal. But the US, Ukraine’s most ardent supporter, has been oddly quiet on the matter.

Instead of publicly endorsing a UN-backed tribunal for the crime of aggression, US lawmakers have opted to make it legal for the US to cooperate with ICC investigations by introducing legislative exceptions that give the Biden administration the flexibility to provide “assistance to the International Criminal Court to assist with investigations and prosecutions of foreign nationals related to the Situation in Ukraine, including to support victims and witnesses.”

The US could therefore technically and financially support the pursuit of justice in Ukraine through the ICC without throwing its total weight behind a special tribunal. However, not all branches of the US government are open to cooperating with ICC investigations, including on Ukraine. According to the New York Times, the Pentagon recently opposed sharing evidence with the ICC because US military leaders feared the move would set a precedent that could lead to the prosecution of US nationals.

Yet a special tribunal for the crime of aggression could still be set up with enough support from UN member states through a vote in the General Assembly, a step that could take months to achieve, its advocates say.

On the first anniversary of Russia’s full invasion, the Assembly passed a resolution that overwhelmingly called for Russia to “immediately, completely and unconditionally” withdraw its military forces from Ukraine and emphasized “the need to ensure accountability for the most serious crimes under international law committed on the territory of Ukraine.” The vote by 141 countries adopting the resolution, which is not binding, suggests that a vote for accountability for war crimes committed in Ukraine could signal the Assembly’s willingness to eventually back a tribunal.

Meanwhile, at the press conference closing the fund-raiser in London, a reporter pressed Britain’s Dominic Raab, also a staunch supporter of Ukraine, on whether he endorsed establishing a special tribunal. Raab’s response revealed a hesitancy similar to that of the US.

“To be honest with you, the discussion is still [inaudible] in its plenary stage,” Raab said. “We understand the importance of [a special tribunal] to the people of Ukraine . . . and I think it’s certainly true to say that for President Zelensky, the overriding crime, above all others, has been the invasion of the question of aggression and we want to try and deal with and support as best we can. But it is a much more complicated question to deal with.”

Reed Brody, a prominent human-rights expert, tweeted about the ICC’s fund-raiser, saying: “Beyond the crimes & evidence, the global value of the #Putin warrant depends heavily on the #ICC’s perceived impartiality. Not a good look for western states to pump even more $ into #Ukraine case as others lag w/o resources”

The spelling of Karim Khan’s name has been corrected throughout the article.

Dawn Clancy

Dawn Clancy is a New York City based reporter who focuses on women’s issues, international conflict and diplomacy. She holds a master’s degree from Columbia University’s Graduate School of Journalism. Previously, she has written for The Washington Post and HuffPost.