MICHEL MARTIN, HOST:
The Russian invasion of Ukraine has raised an old question - is aggressive war illegal? The crime was first introduced more than half a century ago after the Second World War at the Nuremberg Tribunal. Now calls are growing to set up an international tribunal to prosecute top Russian officials. NPR's Deborah Amos has this report.
DEBORAH AMOS, BYLINE: Ukrainian exiles come to church in downtown Warsaw draped in the Ukrainian flag. Their children wear blue and yellow hair ribbons and woven wristbands. They sing familiar hymns, then gather in the church's tranquil backyard after the service to share the latest war stories from home. When the talk turns to war crimes, they say they want accountability from higher up the chain of command all the way to Moscow. Andrei Sheptytskyi, a political science professor in Ukraine before the war, stops to talk as he hands out coffee and cookies.
ANDREI SHEPTYTSKYI: So of course, I would like to see Putin being judged for his crimes. Let's hope that the top criminals will be sentenced at the international level.
AMOS: Top officials can only be tried at the international level, he explains. There is immunity in national courts. He knows that it is a big ask to get the international community to back a war crimes tribunal.
SHEPTYTSKYI: Let's be frank. This will need time, a lot of time, and I'm not sure if this will happen, really.
AMOS: To be frank, he's correct. But the response to the invasion may change the odds. For one thing, 18 countries launched war crimes investigations across Ukraine to document Russia's atrocities. The focus is all on Russia. A nuclear power with a permanent seat on the U.N. Security Council - that is a precedent, says Lawrence Douglas, a law professor at Amherst College in Massachusetts.
LAWRENCE DOUGLAS: There had been many critics of international criminal law saying like, well, it only basically becomes a tool of reckoning with the weak. This is now at least an attempt to reckon with the strong.
AMOS: The reckoning Ukraine's leaders want is something like the Nuremberg Tribunal in 1945, where legal concepts created then are still in use today - crimes against humanity, genocide and the aim to make war itself illegal, to hold leaders accountable for the crime of aggression, says Douglas.
DOUGLAS: It's worth remembering that the Nuremberg Tribunal - that was the very first international criminal tribunal in human history. The companion trial in Tokyo was the second. We had to basically wait close to half a century to have the third.
AMOS: In the 1990s, two more tribunals, the former Yugoslavia and for Rwanda, then the first permanent tribunal, the International Criminal Court - it opened in 2002 - controversial ever since, says Douglas.
DOUGLAS: The ICC has some pretty dramatic limitations. Some of the limitations are the fact that, you know, countries like the United States are not members of the ICC.
AMOS: Russia and China also refuse to recognize the court's jurisdiction. And critics complain it lets the powerful off the hook, and it does leave a legal gap, says Philippe Sands, an expert on international trials and tribunals. The ICC can hear cases on war crimes but not the crime at the center of Nuremberg's legal framework.
PHILIPPE SANDS: Not the crime that I consider to be the most important in this conflict, which is the crime of aggression. It's the only crime that goes to the top table. It's the only way with any degree of certitude that you reach Mr. Putin and those who sit with him at the top table.
AMOS: Sands is working with European lawmakers to create a tribunal at the European Parliament. Other legal experts say a tribunal backed by the U.N. General Assembly is the better precedent. Ukraine gets to choose, says Sands.
SANDS: I think it will all turn on getting their hands on a senior enough figure who has command responsibility rather than someone who was responsible just for following orders.
UNIDENTIFIED PERSON: (Singing in non-English language).
AMOS: At the Presidential Palace in Warsaw, a ceremony to honor those who help refugees. More than 2 million Ukrainians have fled their country. The majority came here to neighboring Poland. The event is sponsored by a Polish think tank, one of the first organizations to collect eyewitness testimonies for future trials. Kateryna Sukhomlinova is an eyewitness, an elected official from Mariupol in eastern Ukraine, a town relentlessly shelled by Russian artillery.
KATERYNA SUKHOMLINOVA: (Speaking Ukrainian).
AMOS: "The conservative estimate is 25,000 dead. But I think it was more based on what I saw, people who were lying dead and they couldn't be buried."
You could walk down the streets of Mariupol and just see the dead on both sides of the street?
SUKHOMLINOVA: (Speaking Ukrainian).
AMOS: "Yes. I was a volunteer emergency responder. I responded to the injured, but I saw a lot of dead. The evil has not been punished. It will escalate. The world made a mistake in 2014. They should have stopped Putin then."
Now she travels to refugee centers in Poland to convince Ukrainians to testify. There must be an international tribunal, she insists. Still, there's a long way to go before anyone in the Russian leadership appears in court if they ever do. Putin has denied all war crimes charges. Fake news, he says. Not a single Russian official or commander has been arrested or captured on the battlefield. However, Oona Hathaway, a law professor at Yale, points out an international tribunal would have the power to issue arrest warrants.
OONA HATHAWAY: A lot of these leaders, Putin included, you know, have billions and billions of dollars located outside of Russia. They have families located outside of Russia. They have their yachts located outside of Russia. It would really close down their world.
AMOS: Leaders in Washington and Europe back Ukraine's military campaign. But Sands says getting the backing for justice is just as important.
SANDS: My major concern is that in five years' time, we find ourselves with a panoply of low-grade Russians being caught, and the main people are off the hook completely. And somehow, we point to these sort of crappy little trials as indicating that justice is done when, in fact, they show the very opposite. That's the main concern for me.
AMOS: It's far from certain that the crime of aggression will have a day in court. Deborah Amos, NPR News.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.
