It would be difficult, in recent history, to find a better illustration of the law of unintended consequences than President George W Bush’s decision to invade Iraq. The underlying fantasy was that a swift and decisive military campaign would be followed by a rapid reconstruction effort, spearheaded by some of America’s finest and most overtly Republican engineering corporations and funded by Iraq’s vast oil wealth. With this achieved, the United States would supervise a political renaissance in the Middle East. Iraq would become an affluent representative of democracy and the dominoes would begin to topple. Democracy and a fairer distribution of oil wealth, protected by the United States’s security umbrella, would pull the rug from under the feet of Arab feudal oligarchs and Islamic fundamentalists alike. After all, who wouldn’t want to live in an ordered, tolerant society that respects its neighbours (like Israel), and where there’s a halal McDonald’s franchise in every air-conditioned shopping mall?

Oh dear. The predictions of Bush, Rummy et al turned out to be no more accurate than the famous remark made by Adolf Hitler just before he unleashed his Blitzkrieg against the Soviet Union: ‘We only have to kick in the door and the whole rotten structure will come crashing