On 19 February 2003, the Guardian published a survey of views on the impending war from leading historians on both sides of the Atlantic. Though the verdicts were varied, the weight of opinion, as you would expect from the Guardian, was anti-war. Most disputed the historical analogies being made by both the pro-war (Munich 1939) and the antiwar (Suez 1956) camps. The Bush and Blair governments were portraying anti-war opinion as appeasement of a dangerous dictator who threatened world peace. Some of their opponents regarded the looming conflict as another Suez, an imperial fiasco revisited.

'I don't think it's a case either of 1939 or of 1956,' Simon Schama argued. 'I'm allergic to lazy historical analogies. History never repeats itself, ever. That's its murderous charm. The poet Joseph Brodsky, in his great essay "A Profile of Clio", wrote that when history comes, it always takes you by surprise, and that's what I believe, too.'

Schama went on to make a fairly clear and thoughtful forecast which suggested that there were some discernible outcomes of the invasion, that history wouldn't necessarily take him by surprise. First, the war would be easy to win. No surprises there. What concerned him most, however, was that there had been extraordinarily little debate about a post-war settlement. This led him to predict 'a teddy bears' picnic for terrorism'. It was a remarkably prescient forecast from a man who believed that history was a series of surprises.

At Yale, Paul Kennedy sounded another cautionary note. There were shades of Artabanus' 'Haste is the mother of failure .. .' in his warning. In the absence of a second UN resolution authorising war, Kennedy said military action would be a folie de grandeur likely to backfire. As for how long the American military remained in Iraq after the invasion, history offered a significant parallel. When Gladstone's government intervened in Egypt in 1882 to uphold order against anti-Western Muslim firebrands, Kennedy noted, it claimed it would leave Iraq soon. 'As it turned out, Britain didn't leave for another 73 years.'

The lessons of history: it's a portentous phrase, but what exactly does it mean? What are these lessons? We're always told that politicians should learn from the past and condemn them because they never do (as if the rest of us are any better at using history to regulate our behaviour). The Guardian's brief survey of historians showed that history offers no certain paths to enlightenment. The nineteenth-century French philosopher Ernest Renan was quite right, surely, when he wrote that 'Getting history wrong is an essential part of being a nation.' Or of being human, he might have added. If there are lessons to heed from studies of the past, they are a gloriously subjective pick'n' -mix. Take what you will and dispute the rest. Whatever you want to draw from a particular historical event to suit your intended course of action is legitimate. Anything suggesting the opposite course of action, however, is a false analogy.

Historians themselves are not shy in acknowledging the limitations of the 'learn from history' thesis. 'History never repeats itself, so anyone looking for parallels between the present situation and past events is likely to be disappointed,' said Richard Evans of Cambridge University, who considered the parallels with both Munich and Suez specious. 'I belong to the school that doesn't put much trust in historical precedents,' said Norman Davies, a fellow of the British Academy and of Wolfson College, Oxford. 'They only show that no precedent ever fits exactly and that history never quite repeats itself.' Michael Burleigh at Stanford agreed. 'Historical analogies are rarely useful,' he argued. He predicted a quick war that Iraqis would regard as 'liberation'.

In an article in the New York Times on 5 January, Michael Ignatieff wrote the following passage whose message could have come straight from Herodotus.

What every schoolchild also knows about empires is that they eventually face nemeses. To call America the new Rome is at once to recall Rome's glory and its eventual fate at the hands of the barbarians. A confident and carefree republic - the city on a hill, whose people have always believed they are immune from history's harms - now has to confront not just an unending imperial destiny but also a remote possibility that seems to haunt the history of empire: hubris followed by defeat.

Ignatieff reminded his readers that the great English historian Edward Gibbon - following Herodotus - had argued that empires lasted as long as their rulers took care not to overextend their natural borders.

Bush's vision of the course of history was different. 'We meet here during a crucial period in the history of our nation, and of the civilised world,' he told an audience of 1,400 at a black-tie dinner hosted by the American Enterprise Institute in Washington on 26 February 2003. 'Part of that history was written by others; the rest will be written by us.'

It was as though Bush and America could simply lift themselves above the forces and currents of history and impose themselves upon it as its sole master, unchecked by other forces, untroubled by unintended consequences. The president's remark reminded me of the famous passage in Herodotus in which Xerxes vents his fury on the Hellespont - the ancient name for the Dardanelles - after a storm has smashed up the bridges constructed for his troops to cross over from Asia into Europe. 'Xerxes was very angry when he learned of the disaster, and gave orders that the Hellespont should receive three hundred lashes and have a pair of fetters thrown into it,' Herodotus wrote. 'I have heard before now that he also sent people to brand it with hot irons.'

As the countdown to war in Iraq gathered pace, the warnings mounted. And in these warnings, history cast a long shadow over the future. In March, Dominique de Villepin, the elegantly tailored French foreign minister, a latter-day Talleyrand, recalled Europe's own history of conflict in a warning to America not to rush to war. The implication was that the United States, with a less traumatic history of war with less history, period - was less inclined to exhaust every diplomatic option to avert conflict.

Bush, like Darius and Xerxes before him, like Nooteboom's Napoleon and every other wartime leader we can think of, dismissed all this anti-war advice. He had his own trusted advisers who wanted war and they carried the day. Like the God of Genesis, they wanted to remake Iraq and the Middle East in their own image. They wanted to break from the region's dictatorial past and forge a democratic future. They wanted to make history.

The war against Saddam, as many commentators, historians and politicians had predicted, did not last long. It began on 20 March. Saddam's government fell on 9 April.

History, however, did not disappear in the euphoria of victory. Writing in the Washington Post on 20 April, Paul Kennedy summoned it to caution against the glib neoconservative assumption that America could remodel the Middle East along democratic lines. 'To be sure, history never repeats itself exactly, but it often deals hard blows to those who ignore it entirely,' Kennedy insisted, advising caution, scepticism and humility. Humility seemed almost entirely absent from Bush's mission to topple Saddam. There was a swagger about the wartime president which offended not only critics of the war but many of its supporters.

For a brief honeymoon period in 2003 American forces were indeed looked upon as liberators in Iraq. The ease with which Saddam's regime was overthrown seemed to justifY Bush's bold attempt to write history. The hawks were in the ascendancy. Democracy was infectious, after all. The talk was of Iran next. And then Syria. It did not take long, however, for a vicious insurgency to take root which cooled the enthusiasm of the president and his advisers to start new wars in the Middle East. It challenged some of America's most basic assumptions about invading the country and contested Bush's determination to place himself beyond the bounds of history.

When Bush announced the end of 'major combat operations' on 1 May, the American death toll stood at 139. In May and June another sixty-seven American soldiers were killed. Bush was unrepentant. On 2 July, he said, 'There are some who feel ... they can attack us there. My answer is bring them on. We've got the force necessary to deal with the security situation.'

In July another forty-eight American soldiers were killed. By the time I flew to Baghdad a year later, on 14 July 2004, the Americans were losing an average of sixty soldiers a month. Clio, the muse of history, was flaunting her 'murderous charm' in classically Herodotean style.