Ukrainian refugees wait at central train station in Warsaw, Poland, on Wednesday. The U.N. refugee agency says more than 4 million people have now fled Ukraine following Russia’s invasion, a new milestone in the largest refugee crisis in Europe since World War II. AP photo

It’s been one week since the Biden Administration formally announced its position that Russians have perpetrated war crimes in Ukraine.

Why does that matter? And what could it mean in the future?

Fortunately, the Robert H. Jackson Center knows a guy that can speak directly to those issues.

A “Tea Time with the Jackson Center” event late last week that featured former Center Board President David Crane, who served as chief prosecutor for the Special Court for Sierra Leone, successfully prosecuting many for violations of humanitarian law as well as the first African head of state for war crimes.

Much has changed about the world and the flow of information in the since Crane worked as an international prosecutor in the early 2000s but the fundamental nature of prosecuting international law remains the same.

“You don’t intentionally target civilians,” Crane said, calling it a “cornerstone by which Putin and his commanders are and will be held accountable. That is a bedrock principle.”

But it’s not just how the war in Ukraine is being handled that is a violation of international law.

“This is textbook violations of the laws of armed conflict,” he stressed. “I never thought frankly… I would see in 2022 this kind of dark age lawless conflict in Europe.”

So what are the laws that could be prosecuted based on conduct that is being observed in Ukraine? Crane suggested that three can be proved in this instance: aggressive war, war crimes and crimes against humanity.

“Nations just don’t attack other nations for no legal basis,” he said. “Doing so is aggressive and is now an international crime.”

He said Putin’s “absurd basis” for “justifying this aggressive act is not even worthy of comment.”

While that might sound straightforward, actually prosecuting the cases themselves is fraught with hurdles.

Crane said social media allows us to watch these acts happen on the ground.

“(It is) important for our colleagues to understand… the rules of procedure and evidence still apply,” he said. The data — which he called a “tsunami” — still must be proven, though there is a “tried and true” methodology to build the case.

Another? Politics.

“Modern international criminal law is a creature of political events,” Crane said. “We’ve got the law down. Politics do play a part. We can prosecute these individuals… but there has to be a political will to create the tribunal” as well as a willingness to hand over the suspects.

There are also options for the venue where the cases can be brought.

One is the International Criminal Court and an investigation into the situation in Ukraine has been opened there.

Crane said another venue is through the United Nations to “create a hybrid international tribunal like the tribunal in West Africa which I created.” He said that could not go through the UN Security Council because Russia would veto.

A regional court is a third option but Crane said that has “political implications because the whole world wouldn’t be standing together.” Domestic courts in NATO member countries are another option.

Crane spoke in support of the UN option, a “Special Court for Ukraine.”

“If we move forward ethically and legally” in that direction, Crane said, “I think it will be a great deterrent” to other strongmen in the world. “I honestly believe this because we’ve already done it before.”

“He knows now there’s no going back,” he said of Putin, who is in a “lose-lost situation. … There’s really no off-ramp for him anymore. Legally, politically and practically he’s done.

“I think it’s critical that once we develop a solid case against Vladimir Putin and his commanders that we do indict him for aggression,” he added, calling it “another way we can show the Russian people… that they’ve gone down the wrong direction.”

These prosecutions can be costly. And they take time.

Crane’s message in light of that was clear.

“I just urge, don’t give up on this,” he said. “This has to happen. We can’t walk away from what is happening in Ukraine or we are going down a very, very dark path. I’m hopeful. I’m very excited (about) what the world has done.

“I think we’re moving in the right direction.”