It is plain for all to see that America's Iraq war has not gone the way the White House had expected.

The political fall out from the failure to find any weapons of mass destruction (WMD) may in the end prove to be the lesser of the headaches for the United States. The Bush Administration probably believed, when it went to war, that Saddam Hussein must have hidden his WMD, not an unreasonable assumption in view of the Iraqi leader's character.

However, the war was not just about WMD, though that was easier to sell to the US public. It was also supposed to change the strategic landscape in the Middle East by building in Iraq a model for the region.

On hindsight, these were audaciously ambitious, even utopian goals. In the debates preceding the war, there were some sober and respected voices who questioned the wisdom of America’ course. They did produce a certain unease in me at the time about whether the old and new conservatives in the Bush regime had really got it right.

However, I dismissed these qualms in the belief that the US Administration probably knew best, since it had many clever people with access to a wide array of intelligence. Surely, I thought, America would have learnt from the Vietnam experience, where the “best and brightest” had also misjudged the enormity of the tasks they would face. Alas, it turns out that a new generation has to relearn the same lessons, even if Iraq's parallels with Vietnam should not be overdrawn.

Now the US has to fight a guerilla war it did not expect and was not prepared for. If it had been anticipated, the calculus of loss and gain could well have dictated a different course from the outset.

It is not easy for a conventional army to shift to counterinsurgency warfare in an alien country. It is especially difficult for the American army to do so because it has no recent experience or expertise in counter-insurgency. Guerillas in the region cannot be defeated without good tactical human intelligence and the requisite Arab-language capabilities that go with that.