Tony Blair is appealing to the heads of Western governments to agree a new world order that would justify the war in Iraq even if Saddam Hussein's elusive weapons of mass destruction are never found.
It would also give Western powers the authority to attack any other sovereign country whose ruler is judged to be inflicting unnecessary suffering on his own people.
A Downing Street document, circulated among foreign heads of state who are in London for a summit, has provoked a fierce row between Mr Blair and the German Chancellor, Gerhard Schröder.
Mr Schröder is in London for a summit of "progressive" governments, convened by Mr Blair, which opens today.
Mr Blair has involved British troops in five conflicts overseas in his six years in office, and appears to be willing to take part in many more.
The document echoes his well-known views on "rights and responsibilities" by saying that even for self-governing nation states "the right to sovereignty brings associated responsibilities to protect citizens".
This phrase is immediately followed by a paragraph which appears to give the world's democracies carte blanche to send troops anywhere there is civil unrest or a tyrant who refuses to mend his ways. It says: "Where a population is suffering serious harm, as a result of internal war, insurgency, repression or state failure, and the state in question is unwilling or unable to halt or avert it, the principle of non-intervention yields to the international responsibility to protect."
A political row with Mr Schröder will add to Mr Blair's difficulties at a time when the American and British intelligence services have fallen out with each other over the question of whether Saddam had been seeking to construct a nuclear bomb.
In Washington, the US government has withdrawn the claim that Iraqi agents were in Niger trying to buy uranium. The head of the CIA, George Tenet, has accepted the blame for allowing this claim to be included in President George Bush's State of the Nation speech, in which it was attributed to British intelligence. The former foreign secretary Robin Cook has challenged Mr Blair to publish any evidence Britain has to back up the uranium story.
He told The Independent on Sunday: "The longer they delay coming up with it, the greater the suspicion will become that they don't really believe it themselves.
"There is one simple question the Government must answer when the Commons meets on Monday: why did their evidence not convince the CIA? If it was not good enough to be in the President's address, it was not good enough to go in the Prime Minister's dossier.
"A month ago I gave Tony Blair the opportunity to admit that in good faith he had got it wrong when he warned of the uranium deal. Now that President Bush has made just that admission it looks as if Tony Blair would have been wise to get his in first."
But Jack Straw, the Foreign Secretary, insisted yesterday the information did not come from British intelligence but from some other, unnamed country, and that it was accurate.
In a letter to the chairman of the Commons foreign affairs committee, Donald Anderson, Mr Straw said: "UK officials were confident that the dossier's statement was based on reliable intelligence which we had not shared with the US."
This public disagreement with the CIA, coupled with anger in Britain over the fate of British suspects held at the US base at Guantanamo Bay in Cuba, forms an awkward background for Mr Blair's visit to Washington on Thursday, when he will meet President Bush.
Dr Hans Blix, the former head of the UN weapons inspection team in Iraq, has told the IoS that he believes the British government "over-interpreted" the available intelligence about Iraq's weapons.
Dr Blix was particularly scathing about the claim made in a British government dossier, released last September, that Iraq had chemical and biological weapons "deployable within 45 minutes".
"I think that was a fundamental mistake. I don't know how they calculated this figure of 45 minutes. That seems pretty far off the mark to me," he said.
The Liberal Democrat foreign affairs spokesman, Menzies Campbell, said: "Day by day the case for an independent scrutiny of the lead-up to the war against Iraq becomes irresistible. Only full disclosure can restore the reputation of this Government."
The failure to find the weapons is damaging public trust in the Prime Minister and his relations with the Labour Party, with many backbench MPs who supported the decision to go to war now saying they might have changed their minds if they had known that the weapons might never be found.
The former international development secretary Clare Short will urge the Prime Minister in an interview broadcast on GMTV today to resign before things get "nastier". This brought a strong rebuke yesterday from the Home Secretary, David Blunkett. He said: "Clare Short is being typically self-indulgent. It is important to get behind the Prime Minister and focus on the things that matter to people, like decent opportunities and economic prosperity. I do not understand why people would plot to try to change the most successful leader in the Labour Party's history."
There was also support for the Prime Minister from his old ally, Bill Clinton. At a London conference organised by Peter Mandelson and attended by the Chilean President Ricardo Lagos, the Canadian Prime Minister Jean Chrétien and hundreds of Labour Party supporters, the former US president urged the left to stop attacking Mr Blair or risk the renaissance of conservatism.
"If we want to prevail we will have to learn how to make our case better," he said. "We're living in a new world in which we will be swallowed whole if we do not, and all the evidence of the good we have done will be lost if we give in to inter-party squabbles on the left and lay down in the face of attacks from the right."
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