Ministers can judge the success of the "war" against terrorism by consulting an unusually useful opinion poll. If the war is a war, it has to be an intelligence war. Muslims close to the al-Qaeda network must be persuaded to give notice of potential atrocity. MI5 has a hotline. (Phone 020 7930 9000 if you see anyone with suspiciously combustible feet.) Calls tripled after 11 September. MI5 said that among the gibberings of fantasists and the settling of private scores were solid leads from plausible informants. Emboldened by its success, MI5 posted the number on jihadi websites, along with a message in Arabic urging readers to help a security service that protects "UK citizens of whatever faith or ethnic group".

Specifically, British fears of mass murder do not always spring from an attempt by the security establishment to increase its budget. David Blunkett, the Home Secretary, says the government's support for American attacks on Afghanistan has made Britain a target. In November, Downing Street released a transcript of an al-Qaeda broadcast in which a spokesman for Bin Laden denounced Tony Blair as one of the "arch-criminals from among the Zionists and Crusaders", and advised British Muslims "not to travel by plane" or "live in high-rise buildings and towers".

The number of Muslims contacting MI5 collapsed after America responded to the murder of its civilians by murdering civilians in Afghanistan. The phones began to ring again when Kabul was taken and the bombardment subsided. Now MI5 is back to where it was when B-52s were disgorging daisy-cutters. The American treatment of prisoners is a threat to national security. Standing "shoulder to shoulder" with Bush may have a price.

If you believe in the merry delusions of the special relationship, the danger should be easy to avoid. Blair would use the influence Britain had won in Washington and tell Bush to abide by the minimum standards of the Geneva Convention.

Whitehall would like to do just that. The Pentagon's decision to release pictures of suspects trussed like oven-ready chickens has given the enemy a propaganda coup. (What does it say about US arrogance and insularity that Washington didn't realise that the pictures would be flashed across the world?) If Downing Street didn't already know, the Mail on Sunday told it that allowing military tribunals to order executions on a majority vote, and without the right of appeal, disgusted conservative as well as liberal opinion.

Instead of standing up for Britain and safeguarding the rights of British soldiers, who will need the protections of Geneva in future wars, Whitehall whimpered. The Foreign Office muttered about not rushing to judgement, and then blustered that the Pentagon was entitled to ignore international law and invent a new class of convict who was neither criminal nor PoW, but someone in a judicial no-man's land.

Three British citizens face interrogation and trial by a kangaroo court. John Walker Lindh, the American caught while fighting with the Taliban, will have his day in court and his rights respected by a civilian judge. The Foreign Office won't complain about the double standard.

American contempt for the Geneva Convention is in character. A short and by no means complete list of the international initiatives that the US refuses to accept includes the Kyoto treaty to limit global warming, the 1972 Anti-Ballistic Missile Treaty, the Nuclear Test Ban Treaty, the UN protocol on the control of biological weapons, the international criminal court, and various attempts to restrict landmines, small arms and money-laundering.

British foreign policy after 11 September was meant to change America - to turn the Bush administration into European social democrats, or at least Christian democrats - by persuading Bush to accept that only co-operation and efforts to alleviate poverty could reduce the threat of Muslim fanaticism. That policy is dead. Britain failed because it overestimated its power and underestimated the self-confidence and bravado of the American right.

At last year's Labour Party conference, Tony Blair set out his stall. America's anarchic unilateralism was criticised, if obliquely: "the international community can achieve more together than it can alone". The Prime Minister talked of removing the causes of terrorism by relieving debt and building infrastructure. The Palestinians, he said, must have "the chance to prosper in their own land as equals with Israel".

If you take Blair seriously, a course that is not always wise, you have to admire his ambition. Moscow has as great an interest in combating armed Islamic extremism as Washington. It has a large Muslim minority, as well as miserable and angry Muslim populations in the states along its southern border. Yet Vladimir Putin behaved like a conventional statesman when America asked for his support in central Asia. He asked for and received military and economic concessions. So did Pakistan and Uzbekistan. Britain hasn't said "give us Kyoto and we'll give you the SAS". Instead, it has tried to make the corrupt cold warriors of Washington love the Guardian.

Writing in that very paper, Charles Clarke, the Labour chairman, clung to the belief that Bush would stand up for universal human rights. The America against which Clarke had demonstrated in his youth, for slaughtering millions in south-east Asia, Indonesia and South America, was gone: it was now a "force for good". There were "indications", he continued, "that the US recognises that it, like all other countries, needs to commit to global solutions to global problems - debt and poverty, the environment and nuclear disarmament".

Al-Qaeda pushed the world to the right, as terrorists invariably do. From Zimbabwe and Pakistan to Uzbekistan and Chechnya, the terrorist threat has been used to legitimise repression and free-fire zones. Wars usually require our leaders to pay lip-service to equality of sacrifice. Not this time. After 11 September, Bush brushed aside the interests of his working-and middle-class soldiers and slashed the taxes of the corporations that financed his campaign. The reckless Star Wars programme was accelerated - even though it will start a new arms race and offers no protection against suicide bombers or "asymmetrical" warriors armed with anthrax and dirty nuclear weapons. Speaking of anthrax, not even germ warfare in Washington could persuade Bush to accept the independent inspectors the UN wants to hire to search for biological weapons. The 11th of September hasn't brought a leftish international settlement: it has confirmed Washington's belief that it can do what it wants in a world that has never seen anything to compare with US military dominance.

The numbers are stunning. Pentagon research and development spending, which is fast widening the technological gap between America and the rest, is as great as the entire budget for the British ministry of defence. America spends more on "defence" than the next nine powers - including Russia, China, Britain, France and Germany - put together. The US didn't need British help in Afghanistan; it could fight the war, and is, in fact, fighting the war on its own, with the assistance of the bribed dictators of Uzbekistan and Pakistan. You may remember that Nato offered the US its support at the start of this mess. Washington ignored the offer, and finished off Nato as a military alliance.

Whitehall's private explanation for its servility is that the only way to change the world is to offer Bush unquestioning public loyalty while seeking to "influence" him in private. Can someone please show me the fruits of this strategy? I met the ideologues of American Republicanism in Washington the other week. They all thought Blair was a great guy who had added a touch of class to US diplomacy that their dolt of a president was unable to provide. But when you asked what Britain would get in return, they looked blank. Of course, they said, America wasn't going to whack up its aid budget or abandon unilateralism, or refrain from attacking Iraq, or order Israel to deliver a kind of justice to the Palestinians as a quid pro quo for Britain's support. Why on earth would anyone think that?

Bill Kristol, the amiable editor of the Weekly Standard, the intellectual Republican journal, exploded when I mentioned Israel: "Do you think we need Blair to tell us what to do in the Middle East?!"

Doubters need only ask whether the position of Palestinians has got worse or better since 11 September. The question answers itself. The "war" against terrorism helps Likud and Hamas, and squeezes out the secular middle ground.

Britain could respond to the failure of Atlanticism by following a Little-England strategy that avoided foreign entanglements. We are the world's fourth-largest economy, and going it alone is not as absurd a policy as it initially sounds. Alternatively, we could push for a strong European Union defence force to balance American power. But the past five months have shown that it is a pathetic fantasy to carry on believing in the "special relationship". The past few days have shown that Britain cannot even protect itself from attack, or stand up for the rights of its citizens by making the modest and reasonable request that America uphold the standards of the Geneva Convention.