'Tomorrow, are you ready to die?' Fadil asked me. He was the chain-smoking owner of the hotel in Jordan I stayed at 13 years ago, soon after the fall of Saddam Hussein. I was 22, had just finished university and was waiting for a ride across the desert to Baghdad, where I would begin working for Iraq's first postwar English language newspaper, the Baghdad Bulletin. I wasn't ready to die and thought I should maybe go home, but gave a watery smile, took a gulp of Fanta and fixed my eyes on the flickering TV, tuned to CNN.

When a war goes wrong, a longstanding British political habit is to establish an official inquiry. They take many forms. Florence Nightingale used the Royal Commission on the Health of the Army (1858-62) to promulgate her views after Crimea. The Second Boer War engendered nearly as many fat volumes as Chilcot. Several covered ‘The Military Preparations … the supply of Men, Ammunition, Equipment and Transport … and Military Operations’, others ‘The Care and Treatment of the Sick and Wounded’. The Elgin Commission took evidence from the military commanders, and the secretary of state for war set up an expert commission to investigate dysentery and enteric fever.

Reactions to the Chilcot Report suggest that the only remaining argument for the Iraq War is that criticism rests on hindsight. Tony Blair explained that he invaded the country 'in good faith', as if that somehow excuses the catastrophe that followed. General Sir Mike Jackson shrugged off responsibility for British soldiers blown up in inadequately armoured vehicles by observing that their fate was unforeseeable: ‘we'll never know,’ he said, if any died unnecessarily. Listening to the deflections of blame, I was reminded of a scholar whose work Tony Blair has long admired. Philip Bobbitt warned in 2004 that the war's critics were making a basic philosophical error. He called it ‘Parmenides' Fallacy’: the mistaken attempt to assess a situation 'by measuring it against the past, as opposed to comparing it to other possible present states of affairs’. The argument sounded clever when I first read it, but not for long.

Iraq's invasion and its aftermath illustrate Lord Salisbury's maxim about the 'optimist view of politics', which 'assumes that there must be some remedy for every political ill, and rather than not find it, it will make two hardships to cure one'. The Chilcot inquiry into the 2003 war in Iraq is a world away from the whitewash obligingly thrown over the venture by Lord Hutton's 2004 report, commissioned by Tony Blair while still in office. Sir John Chilcot's summary findings mount a cumulatively devastating critique of Blair's conduct before, during and after the war.