The moment of triumphalism must have seemed tantalisingly brief to the hawks. Within hours, the photo-op of the toppling of Saddam Hussein's statue was crowded out of the bulletins by scenes of looting and lawlessness. Having won the military conflict, the Bush administration appeared curiously unprepared for what to do next in Baghdad.
For Britain the question of what to do next must start with counting the collateral damage from the war to our international standing. Most immediately, there is the division it has put between us and our major European partners. Labour's objective on taking office in 1997 was to make Britain a partner of equal importance in a triangle with Germany and France. After the divisions over Iraq, Europe is back to a Franco-German axis, with Britain once again the odd one out.
Then there is the damage to our standing in the developing world, where we are now widely perceived to have supported a war not of liberation but of imperialism.
This is particularly true in the Islamic nations. The most difficult strategic question in international affairs is how the west can reach accommodation with the Islamic world. Britain is well placed to contribute to finding the answer because of our multicultural society and tradition of tolerance. Yet the war in Iraq limits our ability to act as an interlocutor with the Islamic and, especially, the Arab nations. The images we have seen of the war in the western media are pale, sanitised versions of the raw pictures of civilian casualties on TV bulletins throughout the Arab world.
Only a year ago, we had a broad, global coalition against terrorism, of which many Islamic countries were members. Now that coalition has evaporated. Instead there is a new source of resentment towards the west. It is hard not to conclude that the net impact is to leave us more exposed to international terrorism. The US and Britain may have demonstrated they are powerful only to make themselves more insecure.
The longer the west tries to run Iraq, the greater will be the resentment. Washington shows no grasp that its determined efforts to keep the UN on the margins are against its own best interests. Bush needs to hand over the running of Iraq to a more legitimate international authority before his army of liberation morphs into an army of occupation. He should heed the advice of Iraq's senior cleric: "You toppled Saddam, now leave."
Nor can the west pretend, after such a dramatic demonstration of its power, that it is a passive spectator in the Middle East peace process. The war in Iraq was justified on the grounds that after a decade Washington had lost patience waiting on Saddam to fulfil his obligations under UN resolutions. Yet the Palestinians have waited three decades for Israel to fulfil its obligations under Resolution 242 to withdraw from the occupied territories.
In short, restoring the standing of Britain throughout the Islamic countries depends on US withdrawal from Iraq and on Israel's withdrawal from the West Bank. The awkward position for us as the junior partner in the coalition is that the key to progress on both lies not in our hands but in those of President Bush.
And here we come to the fundamental foreign policy dilemma for Britain. It is not Iraq. It is not even Europe. It is what kind of relationship we can maintain with the US while it is under neoconservative management.
This is not just a problem for Britain. Everyone else has the same problem of deciding how to operate in a world dominated by a hyperpower on the march.
We are in a unique phase of world history. The US already has military firepower equal to the combined firepower of the next ten big spenders on defence, and under Bush the annual addition to its military spending is more than the entire defence budget of most European nations. On present trends, the US, within this decade, will hit the tipping point at which it will be spending half the global defence budget and will have a superior military capacity to everyone else added together. The world has never been so unipolar.
For Britain, US unilateralism raises particularly acute questions because of the intimacy of our relationship with Washington and the identity of British with American policy.
Tony Blair has pursued a strategy of restoring Britain as the closest, most reliable ally of the US. If there was a model, it was to recapture the special relationship of the Thatcher-Reagan years. The catch is that the Thatcher-Reagan relationship was possible not because one was British and the other American, but because both shared the same perverse domestic priorities and the same malign world-views. While Bill Clinton was at the White House, it was possible to recreate that special relationship of two leaders who shared broadly similar instincts and were comfortable with a common rhetoric.
The strategic error was to attempt to roll forward the relationship with Clinton to his successor. The political calculation was rational enough. Blair was convinced that the Tories would claim that a Labour government could not work with a Republican administration. His rapid moves to make his number with George Bush were motivated by determination to close down this domestic line of attack. The mistake was to underrate the problems of building a special relationship without shared political priorities and common values to provide the foundation stones.
The predictable consequence is that, by partnering a right-wing regime in the US, Blair has left himself without supporters among leaders of the left within the European Union. Instead he is dependent for allies on right-wing leaders such as Silvio Berlusconi - a curious partner for a Labour leader who shot to prominence on the commitment to be tough on crime.
Surveying the past two years of relations with the Bush administration, it is hard to spot what support we have received in return for our loyalty. As a European foreign minister put it to me last year: "We are all amused that Britain gets nothing in return."
Another of my ex-colleagues was startled to be told by a Bush appointee in the US State Department: "To be frank, we are glad you are no longer a foreign minister as your position was closer to the UK than the US." Leaving aside the plonking tactlessness of this observation from a professional diplomat, it gives an interesting insight into the private views of Washington on its supposed ally. The Americans appear clearer than ourselves that there is a gulf between our international perspectives.
The record of Vice-President Dick Cheney illustrates the challenge for a Labour government of finding common cause in world affairs with the Bush administration. As a congressman, Cheney voted against a resolution calling on the apartheid regime to release Nelson Mandela. This put him, not just in opposition to the core positions of European social democracy, but in a different world.
The result has been a lengthening list of issues on which the Bush administration has diverged from our international perspective. The Kyoto Protocol on global warming, the Johannesburg agenda on world development, and the formation of an international criminal court are only the more high-profile of the issues on which Bush has done his best to block priorities of British diplomacy. Bizarrely, given his preoccupation with weapons of mass destruction, Bush has even undermined our efforts to strengthen the protocol to the Chemical Weapons Convention, because US industry would not agree to spot inspections, which might be carried out by citizens of its European competitors.
Perhaps lessons from Iraq are now being learnt in No 10. Blair's swift and public refusal to join the Washington chorus of threats against Syria is all the more welcome for its contrast with our faithful echo of Bush on Iraq.
To question the degree of Britain's complicity with a Bush administration is not to be anti-American. The US is not just the country of George W Bush, it is also the country of Michael Moore, Martin Sheen and Woody Allen. Most Americans did not vote for Bush; indeed the majority of those Americans who did turn out to the polls voted for Al Gore.
Nor will Bush be there for ever. In only a year's time, Blair's aides will be confronted with demands from the White House for subtle but unmistakable signals of endorsement of a Bush re-election. I fear their basic instinct, if they expect Bush to win, will be to oblige. It is vital that they master those instincts: Britain's interest is in a Democratic victory.
Tony Blair is famous for his reluctance to choose between alternatives, but always to seek a third way. But the refusal to recognise that there is a choice between making our number with Bush and maintaining our status in Europe has left us marooned in mid-Atlantic. If the Prime Minister wants to restore Britain's status as a major European player, he must now accept that moving closer to Europe requires, by definition, putting more distance between Britain and Bush.
Robin Cook, Labour MP for Livingston, was Foreign Secretary (1997-2001), and then Leader of the House of Commons until his resignation from the government last month