John Kampfner: The muscular interventionism of John Reid

He is now touted as a serious rival to Brown - a prospect to bring fear to the hearts of any liberal Briton

John Reid does whatever it takes to slay the enemy. His political career is based around a sharp instinct for combat. He is a Jack of all trades, but unlike others who have skipped from one cabinet job to another - John Gummer and Sir Brian Mawhinney under the Conservatives, for example - his fortunes are firmly on the rise. He is now touted as a serious rival to Gordon Brown. It is a prospect that should bring fear into the hearts of any liberal-minded Briton. That, in itself, would be enough incentive for Reid to make a challenge.

In March 2003, I asked Reid to provide a moral context for the impending Iraq invasion. Iraq, he told me, would go down as a socialist war. "We take a view of the world which," he said, "has always been internationalist, which recognises that we not only have rights to defend in the world, but we also have responsibilities to discharge; we are in a sense our brother's keeper globally. Sometimes it requires us to say: 'yes, we will make the ultimate sacrifice'."

Each time I look back at that interview, the more alarmed I become. Reid is not part of the social nexus that was early New Labour - the Campbells, Mandelsons and others whose defence of Tony Blair is based on a personal bond. Reid subscribes, perhaps more than anyone around the Prime Minister, to his philosophy (if that's the right word) of muscular interventionism. It is based in a quasi-Christian reading of international affairs-made-simple. It is very close, far closer than many Blairities would acknowledge, to standard American neo-Conservatism. George Bush's depiction last week of the terrorist threat as "Islamic fascist" is one that Reid would be comfortable with.

One of the most intriguing aspects of modern politics, which long pre-dated the events of 9/11, has been the extent to which the debate about state and the individual has cut across political lines. Those who seek to enshrine the primacy of the individual, even under the duress of a response to terrorism, are spread fairly evenly between the parties. The same goes for authoritarians, except that it is only through the exercise of power that these people come into their own. Reid, Blair and others of their ilk, with the ardent support of much of the media, have seized the authoritarian mantle from the Conservatives. It is often couched in socialist language - "responsibilities", "social cohesion", "struggles". But essentially this is a position in which many on the Right feel comfortable.

Perhaps more than any other issue - such as taxation, equality or the provision of public services - state and security now define our politics. When Reid used his speech to Demos last week to proclaim that his detractors "don't get it", he was speaking from the heart. He also apparently had information that we did not.

When a state feels threatened, it takes some considerable intellectual and political courage to stand up to the authoritarians. Very few in the Labour Party do it, for fear of being attacked in the tabloid press. Brown, as he hides away in Fife worrying about his fate, is certainly not going to stand in their way. If he, Blair and Reid strike up an unlikely alliance on counter-terrorism, anything is possible. A restoration of the 90-day detention period would stand a very good chance of passing if re-submitted to Parliament. As for identity cards, watch Brown's resistance melt. Even the most prudent of Chancellors would open any contingency fund in the "fight against fascism". How the term rolls off the tongue. It already sounds more galvanising than the "war on terror".

Reid is a more complex character than often portrayed. His looks and mannerisms suggest a bruiser. He is more intelligent than that. He is a man of guile and ambition, but a man who thinks about his politics too. His belief in "mutual interdependence" is not that far removed from Brown's, although it is often expressed in different terms.

Like several of the other former Communists in Blair's administration ("I used to believe in Santa Claus, too" is his standard riposte), Reid has discarded the political conclusions, but not the instincts. His conviction that he is always right, wherever he happens to be on the political spectrum at the time, is matched by a determination always to have his way.

In their different ways all the incumbents under this Labour government have either faced, or manufactured, a battle with naysayers in the judiciary and beyond. Jack Straw did it with a trite attack on "Hampstead liberals"; David Blunkett turned it into a speciality and is possibly better remunerated for it now with his column in The Sun. As for Charles Clarke, he was more imaginative in his thinking, but when confronted with the prospect of a political mauling from the Right, he pushed through the various anti-terror laws with alacrity.

The issue at stake is not so much specific counter-terrorism measures but their context. Everyone has their own view about acceptable limits, but even "Hampstead intellectuals" might appreciate the necessity of CCTV cameras, or extra police, longer detentions without trial, or telephone taps - if the rest of our body politic was also working with our security in mind.

And this is where it all falls down. There was no surprise in Reid's reaction to the letter by leading Labour Muslims in which they linked British foreign policy to a sense of alienation that helped to foment terrorism. Reid knew it was good politics to denounce the signatories; but he did so mainly because he passionately believes in what he says, that the fight must be fought wherever and whenever until it is won. That there is no ultimate victory, that Iraq and Lebanon are calamities not just for the region but for us too, appears to have passed them all by. That foreign policy has always been a mix of principle, national interest, and ultra-pragmatism is a point apparently lost on this new generation of arch-ideologues.

In terms of his immediate political fortunes, Reid has done himself considerable good in his reaction to the past week's events. He would still start some way behind Brown in a contest, but he is now a real contender. What matters more, however, is that this high-risk, simplistic, approach to matters of war and peace, which Blair made his own, is now likely to outlast him, whoever is in Downing Street.

The writer is the editor of the New Statesman