I know who I won't be voting for at the general election

Being able to travel to work without being blown up and not having to worry about one's children in their schools matters just as much to people as whether their family has enough to live on. We worry as never before about our personal safety in this era of terrorist outrage. That is why the next general election is going to be different from its predecessors. Security has become a first-order question, along with prosperity and the rule of law.

Being able to travel to work without being blown up and not having to worry about one's children in their schools matters just as much to people as whether their family has enough to live on. We worry as never before about our personal safety in this era of terrorist outrage. That is why the next general election is going to be different from its predecessors. Security has become a first-order question, along with prosperity and the rule of law.

On this aspect of government policy, a conclusion can now be reached. Labour, led by Mr Blair, has made us less safe. The Prime Minister's crusade in Iraq has had a perverse result. The continuing occupation of the country encourages rather than deters militant Islamist groups, cells and suicide bombers, who wreak death from Bali to New York and from Kenya to Russia.

How could it be otherwise when Muslims across the world see US tanks nosing ever closer to mosques in holy cities? How could this not be the case when Iraqi deaths are counted in their tens of thousands, yet go virtually unnoticed by the coalition powers? How could it be different when, as it turns out, Islamist forces seem to be winning?

For American troops have lost control of large sections of Iraq. In areas ceded by them, Iraqis working with the coalition have been ousted and killed. And when the Americans make an agreement to enter a disputed city, as they did last week in Samarra, they are obliged to let local fighters keep their guns. It is questionable whether large numbers of Iraqis will be able to vote in the elections scheduled for January. Remember that one of the justifications for the invasion was that the democratisation of Iraq would lead to the democratisation of the whole Middle East.

Even the cautious Financial Times said on Friday that it was "time to consider Iraq withdrawal" and that coalition forces were part of the problem rather than the solution. Thus this utterly conventional newspaper finds itself in agreement with al-Qa'ida, which had issued a statement the previous day stating that "the defeat of America in Iraq and Afghanistan has become a matter of time ... If they remain they will bleed to death. If they withdraw, they will have lost."

In short, the Anglo-American invasion of Iraq has been an unmitigated disaster. In American post-war history it ranks with Vietnam; in British history with the botched invasion of the Suez Canal in 1956.

In coming to this conclusion, we need not reproach ourselves for being wise after the event. For when the decision was being made, millions of people made clear their disagreement by participating in one of the biggest and most dignified protest marches ever to take place in this country. "Not in our name" was the slogan. And at the same time, major allies refused to join the invasion. We cannot dismiss Germany's and France's reservations as in some way eccentric: their leaders are every bit as grown up and serious as ours. They have electorates, too.

How did Mr Blair get us into the mess? Because he didn't at first see where George Bush, Dick Cheney, Donald Rumsfeld, Condoleezza Rice and Paul Wolfowitz were coming from. He didn't understand from the beginning that they are in thrall to the notion that the United States, as the single superpower, must work its will on the rest of the world. Even, ridiculously, that the US serves God in so doing.

These right-wingers are not conservative in the sense of respecting the wisdom embedded in long-established habits and institutions. Rather they are impatient, aggressive imperialists, seeking not colonies but dominance. Today empire means the political control by a dominant country of the domestic and foreign policies of weaker countries. Don't let's congratulate ourselves any longer about the special relationship. In terms of foreign policy, Britain is part of the American empire; France and Germany are not.

Somewhere in the recesses of his mind, I believe, Mr Blair realised before the war began that he had chosen the wrong course. That is why he couldn't be frank with the British people. Whether he consciously or unconsciously set out to mislead us with the Iraq dossier, we shall never know. But why concern ourselves with whether he was a "sincere" deceiver, to use The Economist's phrase? If we are misled by someone with whom we are doing business, we don't normally spend any time considering their state of mind.

There is everything to play for in the forthcoming general election. But I have already made one decision. I cannot vote for a party led by Mr Blair.

Fortunately that leaves me with plenty of options. I am a "floater" par excellence. I usually cast my ballot for what proves to be the winning party. But as Gordon Brown ponders his future following the Prime Minister's Cabinet reshuffle, I want to say this to him. It is your patriotic duty to replace Mr Blair as swiftly as possible. Britain's relationships with the US , with Europe and with the Middle East need to be recast in a form that enhances our security rather than diminishes it.