This has already been a desperate week for Tony Blair. First, his handling of the Iraq crisis was openly denounced as "reckless" by a member of his own cabinet, Clare Short. He then advertised his growing political weakness by failing to sack her, emboldening parliamentary defiance and triggering the first calls by Labour MPs for his replacement. The following day, as Blair was slow handclapped by a television audience, the French president, Jacques Chirac, appeared to close off Blair's last hope of any new UN security council resolution that could be presented as authorising war by declaring: "Whatever the circumstances, France will vote no."
Now, most gallingly of all, the prime minister has been stabbed in the back by the very US administration for whom he has put his own leadership on the line. By publicly calling into question Blair's ability to join a US attack on Iraq, Donald Rumsfeld was clearly signalling the Pentagon's impatience with the chaotic diplomatic quadrille in New York and letting it be known that Blair's usefulness to his US patrons may be close to being exhausted. Some have suggested the US defence secretary was merely trying to be helpful, but given Downing Street's frenzied reaction and Rumsfeld's unilateralist convictions, that seems deeply implausible.
The two sides were busy talking down the transatlantic rift yesterday, but the worst of the week may not yet be behind Blair. President Bush has insisted there will be a vote on a new security council resolution by the weekend. The terms of the ultimatums being cooked up for it - including a requirement that Saddam Hussein gives a televised confession of his mendacity - make clear it is designed to be rejected by the Iraqi regime and pave the way for an immediate US invasion. And unless Chirac decides to perform a self-defeating volte-face, the expectation must be that the resolution - now mainly being fought for to save Tony Blair's political skin - will be vetoed.
If he sticks with the US none the less, Blair will then find himself at the heart of the political nightmare he has so long hoped to avoid: facing a likely wave of resignations from government, a parliamentary rebellion that might leave him dependent on Tory support, an explosion of mass opposition in the country and the likelihood of a challenge to his position as prime minister. He would also be party to an act of aggression that the UN secretary general, Kofi Annan, warned on Monday would be a violation of the UN charter and therefore illegal.
Without an explicit UN resolution backing war, Blair will face a choice. He could try to ride out the tide of opposition in the hope that the war would be short, the known casualties relatively few and the military occupation at least initially welcomed on the streets of Iraqi cities. Alternatively, but improbably, he could perform a historic u-turn and refuse to take part in an unlawful at tack opposed by a clear majority of the British people. A third option would be to go for a low profile backup role in a US invasion of the kind floated by Rumsfeld and certainly discussed in Downing Street as a possible fallback position over the past few weeks - though that might seem the worst of both worlds, neither pacifying opponents nor offering full entitlement to the political and commercial spoils.
But whichever way he turns, the prime minister will not avoid being seriously damaged by the fallout, either at home or abroad. He is after all a leader who has staked everything on the benefits of his embrace of the Bush administration, his moral determination to act against Saddam Hussein, his ability to lead his own people, his commitment to multilateral action through the UN, his credibility as a principled international statesman. Some, or even most, of these hopelessly inflated claims will not survive the conflagration of the coming weeks. And it is not only Blair, but his government as a whole, that will be irreversibly weakened as a result.
That it has come to this pass is the product of a sustained failure of political judgement from which Blair's reputation can never fully recover. The prime minister now knows that he has decisively lost the battle for public opinion. And as the UN inspectors oversee the destruction of Iraqi missiles, the latest polls suggest that scepticism about the case for war is actually hardening. Blair nevertheless shows every sign of intending to send British troops to war without the consent of the British people. The prime minister argued this week that "you can't actually take these decisions simply by opinion polls". And of course, when it comes to many decisions in government - involving conflicting public views and the need for policy coherence - that argument has some force. But it has no force whatever in the the case of war on Iraq, which has been trailed and exhaustively debated for getting on for a year and about which public opinion has been remarkably consistent all along.
When it comes to issues of life and death, a country's fundamental relationship with the rest of the world and what Blair himself regards as international morality, it is simply absurd to argue that settled public opinion should not be decisive in a democracy. Blair insists that history will be his judge - which may be true in the long run, but in the meantime that role will played by the British people.
A majority say they now regard their prime minister as an American poodle - in other words, the agent of a foreign power - while almost half the British people believe the US is currently the greatest threat to peace in the world. Any doubts as to where the real impetus for war on Iraq came from should have been dispelled by the pattern of events in the aftermath of September 11 2001. For months, Downing Street and Foreign Office officials ridiculed the background chatter coming out of Washington that Iraq would be the next target in the war on terror. Then about a year ago, the briefers went into abrupt reverse - when the US administration took the decision to go for Iraq.
The looming war has plunged Britain into a crisis of sovereignty as well as of democracy. But even if it's sharpest in Britain, because of Blair's role as senior cheerleader for the US, that crisis is also a global one. Across the world, public opinion is now overwhelmingly opposed to war on Iraq, as measured in countless opinion polls, including in those states - such as in eastern Europe - hailed by the Bush administration for supporting US war plans. With the shaky exceptions of Israel and the US itself, there now appears to be no country in the world where a majority backs war on Iraq without UN authorisation. As the established international institutions buckle under the weight, we are witnessing an unprecedented globalisation of public opinion. Those who defy it may find they pay a far higher price than expected.
