Watching Richard Clarke give evidence at the 9/11 hearing was pure political entertainment. To me, the sight of Clarke attacking the President, his former boss, in an election year was enjoyable enough; that Clarke had been one of George W. Bush's top counter-terrorism experts, and a Reagan appointee who had successfully worked with Bush senior, made the experience comparable to Boris Johnson's attempt to present Have I Got News For You.

But, as the 9/11 hearing continued, I noticed a contradiction in my position. Clarke accused Bush of not being sufficiently zealous when hunting down terrorists. I was worried when Bush went into Afghanistan and furious when he invaded Iraq. Yet here I was, cheering on a man that believed Bush should have gone into Afghanistan sooner to prevent the 11 September attacks. And, despite the fact I had spent the last year petrified by the potential consequences of the Bush doctrine of pre-emption, I was quite prepared to agree with him.

What was worse, despite my long-standing concern that Iraq would be a humanitarian nightmare, I found myself cheered by the growing crisis, but only because it made another four years of Bush marginally less likely – an attitude not so much contradictory as sociopathic.

But then, finding a consistent liberal attitude to the War on Terror has never been easy. You try reconciling being anti-war and anti-terror, anti-Bush and anti-Saddam while, all around you, people yell that to criticise the erosion of civil liberties is to support al-Qaida.

In the run up to the war in Iraq, working out exactly what I thought became nearly impossible. Despite my anger that civilians would die and a US-led invasion could destabilise the entire region, I felt there must be some truth in the WMD allegations, if only because I could not believe that Blair would be stupid enough to risk so much – his career, that is, not innocent lives – just for the sake of avenging an assassination attempt against George's dad.

Moreover, I could not quite bring myself to sympathise with the mob mentality of the anti-war protests. I had the uncomfortable feeling that many protesters were not there because of a deeply held concern for the well-being of Iraqi civilians, but because Bush was the bogeyman and war was, like, evil. Last November, if I had asked the 16-year-old girl in purple dreadlocks, standing on a bollard and failing to find takers for her enthusiastic chant of "Go back to Texas!", whether the war could be justified if it prevented more deaths than it caused, I doubt the response would have been a well-considered thesis regarding the finer points of international politics and morality. The anti-war marchers were the purest form of protest, flowing with dissent but short on alternative policies for dealing with the spectre of WMDs beyond "War? No thanks". As much as I agreed with their aims, their perspective seemed narrow.

None of which made it any easier to work out exactly what I thought.

The Clarke affair finally made it click. It was not so much the precedent of unilaterally invading Iraq in the name of world security that scared me, it was the fact that George W. Bush was at the head of the invasion. After all, as any Grenadan will tell you, pre-emptive military action is not exactly new. Bill Clinton embarked on his fair share of such attacks: bombing Iraq, Kosovo and Sudan. Yet the Left never thought he would lead us into a Third World War. What is more, his reputation rapidly switched from dodgy middle-of-the-road pervert to liberal icon about a week after Dubya's inauguration.

The reason why, in contrast to Clinton, Bush terrifies me boils down to the same reason why, however bad Tony Blair gets, I find him infinitely preferable to Michael Howard. Bush, like Howard, is an ideologue. Bush seems to be a man that believes in his actions so strongly that terrorists, voters or facts cannot divert him. He did not need the UN's approval for the war, and stories circulate about him telling dissenters that nobody cares what they think. It is even rumoured he told William Hague that he planned to install Star Wars listening stations across Europe, regardless of what the continent's national governments felt about it. All of this makes it easy to believe that Bush, or maybe one of his advisors, has a pre-formulated plan to remake the world.

This kind of world-shaping agenda is present in both the old Left and new Right, but is notably absent from both Blair's New Labour and Clinton's New Democrats. Their actions, instead, stem from an ad hoc pragmatism. They may seem opportunistic, even sleazy, but at least they base their actions on a response to the reality of the world around them. Conversely, the ideologues seem to act on a pre-set course that they genuinely believe in, regardless of the facts on the ground.

Combine their self-belief with Bush's famed lack of contact with the non-American world, and you get a terrifying mix of ignorance and inflexibility. It is this heady combination, more than the potential of the doctrine of pre-emption, that means Bush's war on terror petrifies me in a way a hypothetical Gore or Kerry war would not.

Bush makes liberals like me uncomfortable by virtue of who he is, as much as what he does. A near unilateral invasion of an unstable region is frightening enough; for a man so sure of his beliefs that other people become an irrelevance to lead the charge, a man that could probably not find Germany on a map, is rock-back-and-forward-under-a-blanket terrifying. Consequently, I want to see his re-election chances demolished for the greater good – even if it means he obliterates large sections of Falluja in the process.

So, as it turns out, complete powerlessness can corrupt absolutely as well.