The Observer view on bringing Assad to justice after a decade of war in Syria

He turned his country into a graveyard. Hundreds of thousands of people have been killed, including 25,000 children. Millions more have been forced to flee. Terrible crimes – war crimes, crimes against humanity, widespread torture, indiscriminate bombing, chemical attacks – have been committed in his name, and continue to this day. Syria lies in ruins. So why, 10 years after the war began, is Bashar al-Assad still in power?

It’s a question with many answers, which boil down to one: inertia. Syria’s dictator-president has survived this long because the international community has allowed it. The UN’s independent international commission of inquiry has produced dozens of damning reports since 2011. Its latest records how tens of thousands of civilians have been “forcibly disappeared” by the regime, or subjected to “torture, sexual violence or death in detention”.

The commission’s chair, Paulo Pinheiro, points to a collective global failure. “Parties to this conflict have benefited from the selective intervention and woeful negligence of the international community that has left no Syrian family unscathed. [Syrians] have paid the price as a brutal, authoritarian government unleashed overwhelming violence to quell dissent,” he said last month.

“Opportunistic foreign funding, arms and other support to the warring parties poured fuel on this fire that the world has been content to watch burn.”

Yet while few will dispute his analysis, even fewer pay him heed. The UN’s reports gather dust. A mountain of evidence has been collected by UN and European organisations – but is not systematically acted on. Assad’s tyranny continues unchecked.

Many other factors have kept his regime in power. One is the refusal of the western powers to forcibly intervene. Pressure to do so peaked in 2013 after Assad’s chemical weapons killed hundreds of people near Damascus. Fearful of another disaster like Iraq, MPs rejected UK military intervention. Days later, Barack Obama and the US Congress followed suit. The then Labour leader, Ed Miliband, said the Commons had spoken “for the people of Britain”. Perhaps.

Assad also owes his survival to the opposite instinct, as exhibited by Russia and Iran. Vladimir Putin’s decision to step in militarily in 2015 almost certainly saved the dictator’s skin and changed the course of the war. Russian forces were accused of war crimes, too, as Assad reconquered roughly three-quarters of Syria’s territory. Pro-Iranian militias played their callous, sectarian part. Again, civilians paid with their lives, their homes, their futures.

Assad is still in power despite the fact his murderous barrel-bombing of opposition neighbourhoods, sarin and chlorine attacks, and air strikes on hospitals, clinics and schools forced more than 6 million Syrians to flee abroad. That exodus stoked a migrant crisis across Europe, for which there are still no humane solutions. Rather than send these helpless victims to remote offshore islands, Boris Johnson and the home secretary, Priti Patel, should instead address a root cause of the problem: Assad.

Assad has thrived on chaos. Outside meddling by Arab regimes made matters worse. Israel regularly bombs Syrian territory to keep its enemies at bay. Turkey generously gave shelter to millions, then spoiled its record with divisive military incursions. The Islamist terrorists whom Assad claims to be fighting profit, like him, from international disarray.

And yet, and yet… even after 10 years, Assad is not untouchable. Tyranny, inertia and impunity cannot be allowed to triumph. If there is ultimately to be any redress, it is most likely to come in the form of legal action – for only this now offers a realistic way to make him pay for his crimes. If the international criminal court continues to be stymied by Russia and China in the UN security council, Britain, the US, EU and other like-minded countries should join forces to establish an ad hoc international criminal tribunal for Syria.

Precedents exist, in the form of the one-off tribunals created to prosecute crimes in former Yugoslavia and Rwanda. There is no good reason why such a court should not be created to try Assad and senior regime figures as well as opposition groups and militias also accused by the UN of war crimes. Prosecutions in national courts of alleged offenders, such as that successfully concluded in Germany last month, should also be prioritised and expanded in scope under the principle of universal jurisdiction.

This terrible tragedy demands a reckoning. If Boris Johnson’s government, for example, really aspires to be a global “force for good” that champions human rights and universal values, it must henceforth insist, in every international forum, at every meeting with Russian, Chinese and other influential leaders, and at the G7 summit it will chair this year, on the establishment of an international tribunal. The US and other allies should act likewise.

The aim is justice. Justice for all those powerless people, living and dead, who have suffered so horrendously. Justice for a nation butchered and betrayed as the world looked on. Justice, most of all, for a dictator whose appalling crimes shame and demean us all. Until Assad stands in the dock, Syria’s war will never truly be over.