'Don't blame us for getting into this mess. Help us get out of it'

Tony Blair has launched the political equivalent of a pre-emptive strike. Last week, in his Mansion House speech, Blair declared that the timing of President Bush's visit could not have been better. Without explaining fully why this was the case the Prime Minister went on to urge opponents of the war to cast aside the old arguments about the conflict: together we should all unite to bring stability to Iraq.

Blair is such a persuasive speaker that sometimes the sheer chutzpah of his message is easily missed. Opponents of the war would never have heard the end of it if the weapons of mass destruction had been found, Iraq had become more stable and peace had broken out in the Middle East. Indeed Blair and his entourage prepared carefully for what was briefly known as the "Baghdad Bounce", in which the triumphant war leader gave a long interview to The Sun newspaper on his delight at the victory and the pressures he had been under until that point. His post-war visit to Iraq was punctuated by celebratory photo-opportunities. There would have been much more of this had the war and its aftermath gone to plan, but now the dissenters are being told to keep their heads down and pull their socks up. Blair's message can be roughly translated as: "Don't blame us for getting into this mess. Help us get out of it."

The Prime Minister was being equally artful in his broader theme. He reiterated his belief that Europe and the United States should work together, with Britain "right in the thick of it". At least he has achieved part of his objective. Britain seems to be in the thick of things, but not in a way that is noticeably constructive. Over the past year Britain has alienated France and Germany, large sections of the UN, moved further away than ever from joining the single currency and become embroiled in a precarious and costly attempt to restore order in Iraq.

As part of his pre-emptive strike Blair suggested that his objective of binding Europe and the US was a "minority one" as if he was crusading boldly against majority opinion. But a desire for Europe and the US to work closely together whenever possible is a widely held aspiration. Pro-Europeans, including the likes of Ken Clarke, Michael Heseltine and Roy Hattersley, are not opposed to strong ties with the US. Most strong Atlanticists would be delighted to work hand in hand with Europe. The problems arise when there is a pivotal and unavoidable disagreement between the two sides. Over the war against Iraq, Blair, like other European leaders, was forced to make a choice. He chose to sustain what he regards as a special relationship and to portray France misleadingly as the only obstacle to a "diplomatic solution", by which he meant a military attack supported by the UN.

Unintentionally, Robin Cook's recently published diaries point to one of the underestimated factors that led Blair to make this decision. Cook describes a Cabinet discussion on the Government's broad political strategy in the spring of 2002. It was not specifically about the international agenda, but Blair must have known that a war against Iraq was a strong probability. Some ministers spoke of the need for the Government to be more radical in its approach to a range of policies, but Blair is quoted as stating emphatically: "We must keep the coalition that we won with twice. We will only get a third term if we keep the coalition between our core vote and the aspirational new voters." Evidently this is his pre-condition before taking any policy decision and explains why he has been cautious about Europe and taxation, policy areas that threaten, in his view, to break up the coalition.

Conversely, among his many calculations over Iraq, he concluded that supporting Bush in a short war would be more popular, or less unpopular, than breaking the special relationship, siding with France and Germany and allowing the Conservative leadership to posture as the party with military backbone. After Bush's election, Blair told allies he was determined not to give the Conservatives any political space as a result of the new situation in the US. He would have as close a relationship with a Republican president as he managed with Bill Clinton. Supporting Bush in a short war was the least bold option for Blair. It neutered the Conservative leadership and retained the support of the newspapers that mattered most to him.

Of course this was not the only calculation, but it helps to answer the question: why was a normally cautious political leader seemingly so politically reckless over Iraq? In terms of his coalition of support, he considered it to be the least reckless choice. The Prime Minister tends to take a robust line only on issues that are not placed easily on the political spectrum. To take another topical example, many senior Conservatives support ID cards or have supported them in the past. Blair is willing to fight hard on this one too.

His determination to remain close to Bush has had two calamitous consequences. In a way that Blair shows little sign of realising, his alliance with the US has undermined his still passionate desire to end Britain's "ambiguous relationship" with Europe. This is close to being a political tragedy for Blair and Britain. Blair is the most pro-European Prime Minister since Ted Heath. In some ways his record on Europe was more impressive than Heath's because it had lasted for much longer. Heath was only in power for three and a half years. It takes stamina and determination to be engaged fully in Europe. Other longer serving Prime Ministers aspired to such a role, but soon lost interest. With a single-minded agility Blair had revived Britain's reputation and influence in Europe, an understated achievement of his early period in power. The reputation is lost now and, as part of that loss, Blair will be in no position to take Britain into the euro even if he wins the next election.

Even more serious, Blair has squandered the opportunity to change the way the country is perceived and sees itself. This is a privilege open only to prime ministers with landslide majorities who do not have to worry all the time about trimming in order to win votes in the Commons. In this respect Clement Attlee made the most of his landslide in 1945. Margaret Thatcher made at least as much of her crushing victories. This week Blair will send out a message that it is Britain's s duty and honour to maintain a close alliance with a right-wing Republican President, especially at times of war. No wonder the Conservatives have convinced themselves that a few cosmetic changes are all that are required to boost their popularity. Too many of their ideas have gone unchallenged by a Prime Minister without the will or inclination to contest them.