PHYSICALLY, Tony Blair looked gaunt and careworn yesterday. A prime minister besieged on every side. Former Tory foreign secretary Malcolm Rifkind had just accused him of presiding over the most disastrous period of foreign policy of modern times, Vietnam and Suez included. Sir Rodric Braithwaite, a former UK ambassador to Moscow and one-time chairman of Whitehall's joint intelligence committee, claimed the current incumbent had done more damage to British interests in the Middle East than even Anthony Eden.

Braithwaite, stooping to some very undiplomatic language, even called Blair "a frayed and waxy zombie straight from Madame Tussaud's", programmed by the CIA "to spout the language of the White House in an artificial English accent". He should go at once, urged this ex-mandarin, every word of his FT column dripping with manicured contempt.

The previous day, United Nations Deputy Secretary-General Mark Malloch Brown broke normal conventions to urge Blair publicly to take a back seat in negotiations to bring hostilities in Lebanon to an early end. It would not be helpful if the team that led on Iraq was again seen to be taking the lead in the latest crisis, warned the Britishborn official.

William Patey, Britain's departing ambassador from Baghdad, had a more nuanced message about the state of affairs back in Iraq. The position wasn't yet "hopeless", he confirmed in his final e-cable to Whitehall, leaked to the BBC. However, the prospect of a lowgrade civil war and the partition of the country is "more likely at this stage" than a successful transition to a stable democracy.

That grim warning was reinforced later yesterday by the top American soldier in the Middle East, General John Abizaid, who told a senate committee that, with sectarian violence in Baghdad now as bad as he had seen it, "Iraq could move toward civil war". The US is so worried it is sending 5000 more troops to Baghdad to shore up defences.

At his own monthly media briefing, the prime minister confirmed his cabinet is split over his handling of the current crisis. He must know the vast majority of his own MPs are in spiralling despair. The chairman of the parliamentary Labour party, Ann Clwyd, a staunch supporter of his in the run-up to invading Iraq, says so. And his plummeting approval ratings in the polls tell their own story.

However, while Tony Blair bears the physical strains of this mounting onslaught, his unshakeable conviction that he is right and his growing army of critics wrong burns brighter than ever. When he made that major foreign policy speech in Los Angeles on Tuesday evening, the initial Downing Street spin was that Blair was advocating a radical rethink of existing strategy on the Middle East. Read what he actually said in the cold light of day and all thoughts of a critical reassessment, let alone a policy U-turn, crumble to dust.

"We must commit ourselves to a complete renaissance of our strategy to defeat those that threaten us, " Blair pledged, characterising that threat as "an arc of extremism now stretching across the Middle East and touching, with increasing definition, countries far outside that region". How he bridled yesterday when asked if his "arc of extremism" was a conscious re-working of George W Bush's original "axis of evil".

The prime minister is now off to the Caribbean for three weeks' holiday. But far from learning any lessons from the daily carnage in Baghdad, the growing insurrection in the British-controlled Basra region, the increased killing in southern Afghanistan, or the mounting civilian slaughter on both sides of the Israel/Lebanon border, there Blair was yesterday hinting that, far from taking Malloch Brown's advice, he'll be heading to the Middle East himself in September in a bid to "revitalise" the search for a two-state solution for Israel and the Palestinians.

Even the Downing Street tea lady can see the gaping holes in your pursuit of a lasting Middle East peace, one questioner observed yesterday. But Tony Blair, with what one editorial called the "cut-glass certainty" he brings to international affairs, doesn't do self-doubt, let alone self-reappraisal. "We will not win the battle against this global extremism unless we win it at the level of values as much as force, unless we show we are evenhanded, fair and just in our application of those values to the world, " he told his Los Angeles audience.

That single sentence is deeply flawed on so many counts. The rise of extremism around the world is not the monochrome phenomenon Blair and Bush think it is. Its roots and its dynamics are local and diverse. And the idea that the antidote is the selective promotion of the values of democracy and individual freedom is proving to be just as misguided. Iraq and Afghanistan are teaching us that democratic government can also be corrupt government. And Iraq is teaching us that even democratic government can harbour repressive, sectarian elements in its midst.

Where is the acknowledgement, in either Washington or London, that replacing the bullet with the ballot box is a dirty business, requiring active engagement, as in Ireland, with those who exploit both before peace eventually arrives? The Palestinians freely elected a Hamas government. And the Lebanese cabinet boasts Hizbollah members. If this is an even-handed battle of values, where are the signs that Tony Blair is prepared to engage with these inconvenient realities?

Persuading others to share your values requires a measure of mutual trust. Tony Blair has already squandered much of that trust at home and across the Arab Middle East by standing "shoulder to shoulder" with George Bush in invading Iraq. They did that, not in a battle of values, but in pursuit of nonexistant weapons of mass destruction, remember.

He has squandered what trust remained in the current crisis in Lebanon. Twice yesterday, the prime minister insisted there had been no "green light" for Israel's armed response in southern Lebanon. The facts of the past three weeks flatly contradict him.

Tony Blair no longer has the moral authority or the political credibility to achieve anything in the Middle East. I don't share Sir Rodric Braithwaite's Szechuan-style way with invective. But it's time the prime minister was told he is now a road block on the road to any progress in the Middle East. If he won't go of his own accord, his anointed successor, the rest of his cabinet and his party should make him.