The empty grave of a man, 59 years old, shot five times in the back by the Russian army during the Russian occupation of Bucha. Bucha, a town on the outskirts of the Ukrainian capital Kyiv, was controlled by Russian soldiers for about a month. Its liberation on March 31 revealed some of the cruellest atrocities committed by Russian soldiers during the occupation. Buildings were destroyed, and houses looted. Dead bodies were found in Bucha streets, buildings and mass graves. (Photo by Rick Mave / SOPA Images/Sipa USA)(Sipa via AP Images)

When an army indiscriminately slaughters and systematically rapes, criminal liability abounds. The soldiers committing inhumane acts are, of course, violating international law, as are their commanders. (This week, Ukraine’s prosecutor general said the country would try a Russian soldier for war crimes, the first such prosecution in the conflict that began this winter.)

And above the officers and generals, there is one person atop the armed forces who must be held to account. In Russia’s war on Ukraine, that is Vladimir Putin. In the last major war on European soil, it was Slobodan Milosevic, president of what was the then-fragmenting country of Yugoslavia. The former president’s story is a bracing one for Putin.

Milosevic’s forces were brutal: In the forests of Srebrenica, they murdered some 8,000 Bosnian Muslims, mostly men and boys. They established so-called rape camps—some in motels—where tens of thousands of Bosnian Muslim women were systematically violated to erase bloodlines, to literally “cleanse” the population of anyone who was not Serbian. The International Criminal Tribunal for Yugoslavia found that a “hellish orgy of persecution” had been committed by Serbian forces in three concentration camps in northwestern Bosnia, where soldiers beat and starved men to death.

The tribunal at The Hague, established in 1993 as the war unfolded, eventually indicted 161 Serbians and sentenced 91. It charged Milosevic in 1999 with war crimes ranging from torture to genocide.

While the tribunal indicted Milosevic, there was no mechanism for extraditing him from Serbia to stand trial. The prosecutor had to ask Milosevic to surrender voluntarily—a feeble gesture. But once Serbian reformists won elections in 2000, they began to investigate and surveil him, and, two years after the former president’s indictment, the government transferred Milosevic to The Hague. He died in a jail cell in 2006 while his trial was still ongoing.

No matter how Russian war criminals are charged, the extradition of Putin, just as with Milosevic, won’t happen while he’s in power, and a successor may be reluctant to hand Putin over—unlike the Serbian reformists with Milosevic. But what happened with Milosevic, as with the Nuremberg trials following World War II, shows that top leaders can be held to account.

What do prosecutors do if Putin remains safely ensconced behind the Kremlin’s walls? If international authorities cannot extradite him, they may be able to try him in absentia, as was done with former Chadian President Hissène Habré, who had been living safely in Senegal for 17 years. A controversial mechanism, the last time trial in absentia was used was in 2009, at the Special Tribunal for Lebanon, which was established at the request of the Lebanese government primarily to try the individuals who killed former Prime Minister Rafic Hariri in 2005.

But it’s important to note that arrest warrants alone bring consequences. “At a minimum,” the Yugoslavian tribunal noted, “the arrest warrants made it impossible for Slobodan Milosevic to leave Yugoslavia,” lest he be apprehended. There was also an order to freeze his assets given by the prosecutor to United Nations member states, as well as Switzerland, which was not a UN member until 2002.

Ukraine’s own Criminal Procedure Code says that a pretrial investigation may be held in absentia for those in hiding. But there are legal hurdles to overcome to get to trial—whether in person or in absentia—including the amassing of physical evidence, witness accounts, and other documentation that can distinguish a war crime from the horrors of war. Getting an indictment is no easy feat, and conducting a trial without a defendant present isn’t the same as having, say, the Nazi leader Hermann Göring in all his hateful glory in the dock. (The Luftwaffe commander took his own life using a cyanide capsule just a couple of hours before he was scheduled to hang.)

“To conduct a trial without the accused is like trying to stage Hamlet without Hamlet,” according to the Asser Institute, an organization based in The Hague that researches European legal developments. “The story of Hamlet cannot be fully told without the Prince himself on stage. It would not be the same play.”

Another means of bringing Putin to justice are “red notices” issued by Interpol, the international consortium of police. Such notices are requests to law enforcement worldwide to locate and hold a person—pending the issuance of a formal extradition request or the suspect’s surrender. The notices provide date of birth, eye color, and other information about the accused (picture Putin’s mug on a wall of the “most wanted” at your local post office). And they allow for an alert to be issued simultaneously to member countries to be on the lookout for the named suspect, making it difficult for him to travel. Regardless, red notices are not international arrest warrants.

A third possibility for justice is “universal jurisdiction.” This complex legal device is being used to convict Syrian war criminals in Germany. (Syria’s legal system has been all but obliterated.) Already, a German court has convicted a Syrian colonel of crimes against humanity and given him a life sentence in what is being hailed as a landmark case. It was also used to convict Adolf Eichmann in Israel in 1961, arrest former Chilean President Augusto Pinochet with a warrant issued by Spain, and extradite John Demjanjuk—an accused Nazi concentration camp guard—from the United States to Israel in 1985.

Think of universal jurisdiction as the way to try perpetrators of crimes so heinous that the world must act regardless of where the crimes were committed. It can act as “a safety net” when the country that commits grave crimes like genocide or terrorism “is unable or unwilling to conduct an effective investigation and trial,” according to Human Rights Watch. “The application of universal jurisdiction reduces the existence of ‘safe havens’ where a person responsible for grave crimes such as war crimes, crimes against humanity and genocide could enjoy impunity.”

But universal jurisdiction is a last resort, and rarely used. It, too, requires cooperation between states to extradite a suspect.

War crimes investigators say that what is happening in Ukraine is unlike any major war in modern memory. The crimes are not taking place in a lawless country, as in the Democratic Republic of Congo, or in one that’s both lawless and under dictatorial control, such as Syria. Because there is a functioning legal system in Ukraine, investigations and prosecutions must be done in conjunction with the Ukrainians.

Right now, there are hundreds of ongoing investigations of Russian atrocities in Ukraine, legal and investigative experts have told me. Governments, NGOs, and the like have flooded the country with photographers, translators, investigators, attorneys, and others who can document Russian atrocities and gather enough evidence for indictments. While war crimes experts hope to see arrests, trials, and convictions of Russian war criminals—from the on-the-ground perpetrators to Putin himself—they know that justice will take years to deliver, if it comes at all.

Still, one fact offers comfort to investigators: While the arrest and trial of Putin and top Russian officials is a distant possibility right now, war crimes have no statute of limitations. Nonagenarian Nazis are still being prosecuted decades after World War II. The world will likely have to wait for legal justice for Ukraine, and it may never come. But with no time limit on their apprehension, Putin and Russia’s other war criminals must always remain on edge, fearing the tick of the clock.

Lauren Wolfe

Follow Lauren on Twitter @Wolfe321. Lauren Wolfe, a Washington Monthly contributing writer, is an award-winning journalist and the author of Chills, a Substack newsletter. She is also a professor at NYU's Arthur L. Carter Journalism Institute.