On April 1, 2001, Slobodan Milosevic, the former president of Serbia (1989-1997) and president of the Federal Republic of Yugoslavia (1997-2000), surrendered to police special forces to answer charges of genocide and crimes against humanity arising from his leadership role in the wars in Bosnia, Croatia and Kosovo.

Milosevic died in February 2002, before his trial by a U.N. tribunal in the Hague was concluded. His Bosnian Serb ally Radovan Karadzic and the Bosnian Serb military leader, General Ratko Mladic, were successfully prosecuted and are both serving life sentences. Their arrest and prosecution for war crimes created an interesting precedent that Vladimir Putin should take note of.

Presidents and their henchmen are not exempt. The post-war trials of Nazi leaders at Nuremberg set an example that was quickly followed by the trial of Japanese military leaders and the updating of the Geneva conventions.

War crimes are defined, inter alia, as the deliberate or wilful targeting and killing of civilians and the destruction of property not justified by military necessity.

President Joe Biden called Putin a “war criminal” for his bombing of hospitals, maternity wards, schools and kindergartens and regular airstrikes and shelling of residential areas by the Russian armed forces.

Few would disagree with Biden’s assessment.

The intentional airstrike of the drama theatre in Mariupol where over 1,000, mostly women and children were sheltered, could certainly be called a war crime. The word “children” had been written in huge Russian letters on each side of the venue.

It is believed that more than 300 died in the dust and rubble of the collapsed building. As the person who ordered the invasion of Ukraine, Putin has clear "command responsibility." Even if he did not directly order the grave breaches of the Geneva conventions that have occurred, he patently was in a position to know about them and yet failed to do anything to stop them from happening.

As such, he can be held legally responsible. Although Russia is not a signatory to the International Criminal Court (ICC), Putin could nevertheless be hauled before a special tribunal set up by the U.S., U.N., NATO and the EU.

Putin’s favorite general, Mikhail Mizintsev, should also be indicted for war crimes, crimes against humanity and genocide. Dubbed "The Butcher of Mariupol" for his relentless bombardment and wanton destruction of that city, Colonel-General Mizintsev had previously honed his skills in the leveling of the ancient Syrian city of Aleppo.

In 2016, Russian forces under Mizintsev’s command, joined with pro-Iranian Shi’ia militias, Hezbollah and Bashar al-Assad’s military, to bombard Aleppo into submission, almost wiping it off the map. He has used precisely the same tactics in Mariupol. He almost certainly ordered the airstrike on the drama theatre, the missile strike on the maternity hospital and the other atrocities in that beleaguered city, where over 100,000 people remain trapped, without food, water or heat, facing a humanitarian catastrophe.

Putin’s solid collaborator in Syria has been the crazed fanatical supreme leader of the fundamentalist Iranian regime, Ayatollah Ali Khamenei, who, unsurprisingly, has supported the Russian invasion of Ukraine and blamed the Americans for instigating the war.

Facing the collapse of the Iranian economy in the wake of decades of corruption, sanctions, untrammeled financing of proxy wars in Syria, Yemen, Iraq and Lebanon and an accelerating bid to build a nuclear weapon, Khamenei desperately engineered the sham election of Ebrahim Raisi as president of Iran. Khamenei hoped that this hard-line religious hanging-judge, known as "The Butcher of Tehran" for his central role in sentencing over 30,000 political prisoners to death in 1988, would frighten the West into lifting sanctions and re-joining the tattered nuclear deal, abandoned by Trump in 2018.

Khamenei’s plan has backfired spectacularly. When Iranian/British survivors of the 1988 massacre heard that Raisi was intending to travel to Glasgow in November last year to attend the COP26 climate change summit, they lodged a dossier of evidence with the Metropolitan Police and Police Scotland, calling for his arrest for crimes against humanity and genocide, under universal jurisdiction. Raisi quickly canceled his plans to go to the U.K.

He would also have learned that the ICC had just launched a full probe into Rodrigo Duterte, the president of the Philippines, for his involvement in crimes against humanity and murder, for the extra-judicial killings in his so-called "war on drugs."

The message must surely now be clear to Raisi, Khamenei, Bashar al-Assad and Putin that being a president does not provide impunity for crimes against humanity and human rights abuse.

Universal jurisdiction enables a state to claim criminal jurisdiction over an accused person regardless of where the alleged crime was committed and regardless of the accused’s nationality.

In March 2016, only six years ago, Karadzic was found criminally responsible for the horror that tore Yugoslavia apart, led to the deaths of over 100,000 people and caused more than 2 million to flee their homes.

Sentencing him to 40 years in jail for ethnic cleansing and crimes against humanity, the judge told him that he was the author of a plan “to commission murder, terror and unlawful attacks against civilians.”

The parallels with the horrors unfolding in Ukraine are disturbing. Thousands are dead. Men, women and children have been murdered. Women have been raped. Over 10 million people have been forced to flee their homes. Cities have been raised to the ground. These are egregious war crimes and crimes against humanity for which those responsible must be held accountable.

There must be no impunity for monsters like Ebrahim Raisi, Ali Khamenei, Bashar al-Assad, Vladimir Putin and their henchmen. The civilized world must hold them to account.

Struan Stevenson is the Coordinator of the Campaign for Iran Change (CiC). He was a member of the European Parliament representing Scotland (1999-2014), president of the Parliament's Delegation for Relations with Iraq (2009-14) and chairman of the Friends of a Free Iran Intergroup (2004-14). Struan is also Chair of the In Search of Justice (ISJ) committee on the protection of political freedoms in Iran. He is an international lecturer on the Middle East and is also president of the European Iraqi Freedom Association (EIFA).