Is it time for Tony Blair to reconsider his relationship with George Bush?

In his interview with The Independent, the Prime Minister insisted that he would remain "shoulder to shoulder" with George Bush, despite mounting pressure to distance himself from the Americans. Photographs showing the mistreatment of Iraqi detainees in US-run prisons brought to a head months of seething dissatisfaction with Mr Blair's closeness to Washington, which is undoubtedly a political liability for him at home.

In his interview with The Independent, the Prime Minister insisted that he would remain "shoulder to shoulder" with George Bush, despite mounting pressure to distance himself from the Americans. Photographs showing the mistreatment of Iraqi detainees in US-run prisons brought to a head months of seething dissatisfaction with Mr Blair's closeness to Washington, which is undoubtedly a political liability for him at home.

Now no politician, least of all one as adroit as Tony Blair, is going to admit that there is any need to change course when such a major joint enterprise as Iraq is going as badly as it is. The words will be of toughness and constancy. But Mr Blair has a particular dilemma. If he heeds calls to dissociate himself from George Bush, he may please his backbenchers and find a little more favour with voters, but he will do nothing to change the situation on the ground in Iraq. Worse, from his point of view, any shift would amount to an admission that two crucial choices of his premiership were both wrong: his determination to show that a Labour government could be a loyal ally even of a Republican administration, and his decision to join Mr Bush in invading Iraq. These are not small mistakes.

Yet it is high time that Mr Blair reconsidered relations with Washington. The disaster playing out in Iraq is only the most visible evidence that Mr Blair's path and Mr Bush's should diverge. However differently Britain may have run the area of southern Iraq for which it is responsible, we are now utterly tainted by association with the Americans. Our stock in the region is just as low, the damage to our diplomacy as enduring.

One reason for supporting the US war given by the Blair government was the chance to exercise some influence over Washington. Yet there is no proof that Mr Blair has been able to influence Washington at all, beyond - perhaps - Mr Bush's agreement to work for a while through the UN. The Prime Minister's most recent US trip, hard on the heels of Mr Bush's public support for Israel's unilateral peace plan, showed just how little Mr Blair's views count in Washington. Any hope of reward for loyalty beyond the call of duty, the quid pro quo on Middle East peace that Mr Blair had sought, was dashed.

It is too late now to speculate about how and even whether Britain's relations with the US would have deteriorated had Mr Blair left the US to fight in Iraq alone. Britain stayed out of Vietnam without apparent damage either to the military alliance or to the tenuous "special relationship". But the Iraq war and its aftermath pose legitimate questions about the value of either. How useful are such arrangements as intelligence-sharing or Britain's share in Washington's nuclear deterrent? We are allied anyway through Nato. Might not the imbalance of power be too great now to leave any substance in the much-vaunted specialness of the bilateral ties?

Mr Blair clearly feels he has no alternative but to stick with Mr Bush for the time being. But he should be think seriously about an alternative to the outdated "special relationship" for the future.