ITV News Correspondent John Ray examines what precedent there is for those found guilty of war crimes facing punishment
With investigators from the International Criminal Court (ICC) on their way to Ukraine, the UK says it will help to track down the generals who might have carried out war crimes there.
By beginning its investigation now, the ICC can start collecting evidence before it is destroyed - whether deliberately or by the passage of time.
But because Russia doesn't recognise the authority of the court, there is little chance President Vladimir Putin himself will be put on trial.
What are the alleged war crimes under investigation?
A war crimes investigation has begun after Boris Johnson accused Putin of committing atrocities by bombarding cities in his invasion of Ukraine.
The ICC opened an investigation on Wednesday night after Britain and 37 allies referred Russia over what the Prime Minister described as “abhorrent” attacks.
There have been several alleged cases of bombings targeting residential areas in Ukraine, and sometimes even the use of banned cluster bombs, which can cause widespread death and injury.
Russia says it only goes for military targets and even claimed Ukrainian nationalists are using civilians as human shields – evidence on the ground clearly does not corroborate this.
More than 2,000 civilians have died since the invasion began, Ukraine’s state emergency service said, although that figure has not been independently verified.
Has a political leader ever been convicted of war crimes?
After the destruction of the former Yugoslavia it took years to track down and put on trial former Serb leader Slobodan Milosovic, who died in 2006 before a verdict was reached.
And Radovan Karadich, the former Bosnian Serb leader, is finally serving a life sentence for genocide relating to Srebrenica in 1995.
The process can be extremely time-consuming and evidence hard to collate.
So how can they gather evidence against Putin?
In Ukraine, satellite technology and social media make is hard for war crimes to stay hidden.
On Tuesday, Dan Rivers reported from Kharkiv - which used to be a normal bustling city but is now an shell
Adam Rutland, of the Centre for Information Resilience, told ITV News: “We’re able to get that footage, we’re able to verify it, we’re able to handle it, archive it in a way that international prosecutors can use when the time comes.”
He added: “They should be able to track down the guilty.”
Does that mean Vladimir Putin could be put on trial?
This could prove difficult in practice, as Russia does not recognise the authority of the court.
But Wayne Jordash QC, a human rights lawyer in Ukraine, said: “Putin controls the oligarchs, Putin controls the crimes on the ground, so I don’t think there is any reason why you wouldn’t go after Putin.”
ICC prosecutor Karim Khan said work would begin “immediately”, with his team already collecting evidence, after the co-ordinated referral freed him to get to work without the need for judicial approval.
Mr Johnson warned the Russian president he “cannot commit these horrific acts with impunity.”
Ultimately, no legal process will stop the Russians in their tracks.
But perhaps it could give their commanders - and perhaps some in the Kremlin - pause for thought.
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