Unfortunately for Mr Blair, and President Bush, too much has happened for the American or British publics to give them the benefit of the doubt any longer. Pictures of the abuse of Iraqi prisoners and daily reports of the killing of coalition forces and of car bombings remain more powerful than assurances that, at last, the right policies are in place.

Iraq is now a major, possibly career-destroying, liability for Mr Blair, which will unquestionably damage Labour in the June 10 elections and in next year’s general election. This is not so much about the hand-wringing and second thoughts recently of politicians and commentators about whether the invasion itself was right.

The real doubts are about what has happened in Iraq since the toppling of Saddam Hussein’s regime. It is these events, rather than the invasion, that have caused the most damage to Mr Bush and to Mr Blair.

But Mr Blair has been tied into American policies and behaviour. His public response has been almost Panglossian, to ignore troubles and setbacks, and to focus always on the future. This approach can be seen as either resilient or self-deluding, as well as politically unavoidable.

The increasing frustration of British diplomats and commanders with the American approach was shown by the well-timed leak on Sunday of the candid Foreign and Commonwealth Office memo. After the Abu Ghraib scandal and the fall in Mr Bush’s ratings, the Government is in a stronger position to push for the “genuine and real transfer of sovereignty to the new Iraqi Government” after June 30, pressed yesterday by Mr Blair.

Talk of publicly “distancing” Britain from Mr Bush is silly gesture politics, but there is scope for defining Britain’s approach more clearly and being more robust. This is essentially what Michael Howard was on about last week.

Mr Blair needs to be more explicit about his strategy for Iraq, both ends (which few dispute) and means. This is not about setting a deadline for withdrawal of British troops. How long they stay will depend on how long it takes to train and build up Iraqi security forces.

Yet, while admitting “a lot of difficulties along the way”, Mr Blair, like Mr Bush, is apt to dismiss those involved in attacks and car bombs as merely “people who are trying to stop us rebuilding Iraq”. But, as the leaked memo said, the insurgents have “a reservoir of popular support, at least amongst Sunnis”.

Given where we are, what Mr Blair said yesterday about Iraq after June 30, and the draft UN resolution, was sensible. In the short term, there is no real alternative. The real time for considering withdrawing troops will be next year after elections in Iraq.

Voters in Britain and America may be less patient. As the leaked memo says, after June 30 “we shall want to minimise the profile of coalition forces and get the Iraqis out in front as much as possible”. If this does not happen, and the violence gets worse, Mr Blair will no longer be able to appeal to his good intentions.

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