Archbishop Desmond Tutu has called for Tony Blair and George Bush to be hauled before the international criminal court in The Hague and delivered a damning critique of the physical and moral devastation caused by the Iraq war.
Tutu, a Nobel peace prizewinner and hero of the anti-apartheid movement, accuses the former British and US leaders of lying about weapons of mass destruction and says the invasion left the world more destabilised and divided "than any other conflict in history".
Writing in the Observer, Tutu also suggests the controversial US and UK-led action to oust Saddam Hussein in 2003 created the backdrop for the civil war in Syria and a possible wider Middle East conflict involving Iran.
"The then leaders of the United States and Great Britain," Tutu argues, "fabricated the grounds to behave like playground bullies and drive us further apart. They have driven us to the edge of a precipice where we now stand – with the spectre of Syria and Iran before us."
But it is Tutu's call for Blair and Bush to face justice in The Hague that is most startling. Claiming that different standards appear to be set for prosecuting African leaders and western ones, he says the death toll during and after the Iraq conflict is sufficient on its own for Blair and Bush to be tried at the ICC.
"On these grounds, alone, in a consistent world, those responsible for this suffering and loss of life should be treading the same path as some of their African and Asian peers who have been made to answer for their actions in The Hague," he says.
The court hears cases on genocide, crimes against humanity, and war crimes. To date, 16 cases have been brought before the court but only one, that of Thomas Lubanga, a rebel leader from the Democratic Republic of the Congo (DRC), has been completed. He was sentenced earlier this year to 14 years' imprisonment for his part in war crimes in his home country.
Trials under way include those of the Serbian general Ratko Mladic and former DRC military commander Jean-Pierre Bemba Gombo. Arrest warrants have also been issued for several suspects, including the Sudanese president, Omar al-Bashir, and Muammar Gaddafi's second son Saif.
Tutu's broadside is evidence of the shadow still cast by Iraq over Blair's post-prime ministerial career, as he attempts to rehabilitate himself in British public life. A longtime critic of the Iraq war, the archbishop pulled out of a South African conference on leadership last week because Blair, who was paid 2m rand (£150,000) for his time, was attending. It is understood that Tutu had agreed to speak without a fee.
In his article, the archbishop argues that as well as the death toll, there has been a heavy moral cost to civilisation, with no gain. "Even greater costs have been exacted beyond the killing fields, in the hardened hearts and minds of members of the human family across the world.
"Has the potential for terrorist attacks decreased? To what extent have we succeeded in bringing the so-called Muslim and Judeo-Christian worlds closer together, in sowing the seeds of understanding and hope?" Blair and Bush, he says, set an appalling example. "If leaders may lie, then who should tell the truth?" he asks.
"If it is acceptable for leaders to take drastic action on the basis of a lie, without an acknowledgement or an apology when they are found out, what should we teach our children?"
In a statement, Blair strongly contested Tutu's views and said Iraq was now a more prosperous country than it had been under Saddam Hussein. "I have a great respect for Archbishop Tutu's fight against apartheid – where we were on the same side of the argument – but to repeat the old canard that we lied about the intelligence is completely wrong as every single independent analysis of the evidence has shown.
"And to say that the fact that Saddam massacred hundreds of thousands of his citizens is irrelevant to the morality of removing him is bizarre. We have just had the memorials both of the Halabja massacre, where thousands of people were murdered in one day by Saddam's use of chemical weapons, and that of the Iran-Iraq war where casualties numbered up to a million including many killed by chemical weapons.
"In addition, his slaughter of his political opponents, the treatment of the Marsh Arabs and the systematic torture of his people make the case for removing him morally strong. But the basis of action was as stated at the time.
"In short, this is the same argument we have had many times with nothing new to say. But surely in a healthy democracy people can agree to disagree.
"I would also point out that despite the problems, Iraq today has an economy three times or more in size, with the child mortality rate cut by a third of what it was. And with investment hugely increased in places like Basra."