At the time of writing, US and British armed forces have been in Iraq for three years. The invasion and occupation of that country has caused more controversy in US foreign policy than any other single event since the Vietnam War. With the benefit of hindsight, it is easy for critics to point to the difficulties the Coalition has faced in trying to counter a violent insurgency as a reason why the invasion should never have occurred in the first place. Moreover, it has become evident that one of the major justifications for invading Iraq – thwarting the regime’s attempt to revive its weapons of mass destruction programme – was based on a false premise, deliberate or otherwise. Nevertheless, one should avoid falling into the trap of historical determinism, and instead base any assessment of the reasons for invasion on what was known at the time. Unless, or until, new evidence emerges, perhaps from key members of the Bush Administration, any other approach would be ahistorical and likely only to feed those intent on seeing conspiracy theories in every action of the administration.