Renewed disarray this weekend in the Bush administration over whether Iraq had weapons of mass destruction comes at a very awkward time for the British prime minister, Mr Tony Blair.
He faces the most gruelling week of his career over the Hutton report dealing with the related issue of whether he authorised publication of Dr David Kelly's name as the source of a BBC report on such weapons. Mr Blair's intelligence reports saying Saddam Hussein's regime had them were the central justification for going to war in coalition with the United States. The resignation of Mr David Kay, head of the US Iraq Survey Group, who says he does not now believe they existed, is a grave embarrassment for supporters of the war.
British and American official statements that the question is still open are less and less credible after Mr Kay's resignation. Such doubt is given added force by Mr Colin Powell's frank acknowledgement yesterday that Iraq may not, after all, have had such weapons. The United Nations arms inspectors say they are not surprised by these findings, since they coincide with their well-publicised conclusions before the war. It is not a trivial point. Despite the several supplementary reasons for going to war put out before and after it by the Bush administration, the allegation that Saddam Hussein had weapons of mass destruction which he was prepared to use against other states was the basic justification offered to domestic and international opinion and the most plausible one under international law.
Confirmation that it was based on poor intelligence and faulty judgment comes at a difficult time for the post-war coalition occupying Iraq, led by the US and Britain. The war did not have an explicit UN mandate, and nor does the subsequent occupation.
The other major failing of pre-war preparations by the coalition - about how to reconstruct Iraq and prepare it for democratic sovereignty, are also becoming more and more apparent.
Resistance to the occupation is growing, reinforced by the delays in restoring basic infrastructure and public facilities - and notwithstanding genuine progress made and the delight of ordinary Iraqis that the dictatorship is gone. There is a growing demand for direct elections as a prelude to restoring Iraqi sovereignty in order to ensure the occupation does not continue under another name. The coalition has had to turn back to the UN and to its European allies for help with these tasks. There are indications the US is prepared to consider direct elections and open up reconstruction contracts to Russia, Germany and France in order to get it.
These questions must be settled through the UN Security Council and spelled out in a new resolution providing a firm and legitimate framework in international law for Iraq's return to democratic sovereignty. Mr Blair's major political calculation throughout the Iraq crisis has been to preserve his country's special relationship with the US. Assuming he survives this crucial week he would be well advised to insist that the UN route is the best way to go.