No prizes for guessing the tipping point:
Blair's ultimate tragedy … did not get fully under way until after the horror of 11 September 2001. A warning sign was the astonishing mixture of hubris and hysteria that ran through his speech to the Labour party conference immediately after the atrocity. Al-Qaeda's attack on the twin towers, he told his followers, marked "a turning point in history". In the new world that it had brought into being, Labour's mission extended far beyond the British isles. It was to "fight for freedom" right across the globe. And, in a passage echoing Winston Churchill, one whose full significance would not become clear for many months, he promised the American people: "We were with you at the first. We will stay with you to the last."
Though few saw it at the time, those two sentences marked the end of the glory years that had begun when Blair crossed the threshold of No 10 in 1997. Rhetorically and emotionally, he had tied himself to the most reactionary US administration of modern times.
From then on, his doom was as inexorable as Macbeth's after Duncan's murder. Each downward step followed inevitably on the one before. The decision to wage war on Saddam alongside the Americans; the decision to present what was in fact a war for regime change as a war to eliminate Iraq's weapons of mass destruction; the decision to lean on the security services to fit their findings into a politically convenient mould; the decision to defy the United Nations and betray the core principles of the European Union; and the monstrous final decision to commit British troops to battle against the manifest will of the British people formed a seamless web of delusion, illegality and self-immolation. The horror that is post-Saddam Iraq, with its spiral of sectarian violence and its mounting death toll, cannot be laid at Blair's door alone. Britain's contribution to the calamity is far smaller than America's. But morally, even if not numerically, Blair is as guilty as George W Bush.