The world, it was said, had changed for ever after 11 September 2001. Since 1945, international conflicts had had only a limited effect on western homelands, particularly the American homeland. Now London, New York and Paris could no longer feel safe; ruthless terrorists threatened the deaths of millions; the west faced a new kind of enemy with whom it was impossible to treat; the gloves would have to come off; there could, in George W Bush's words, be no hiding place. We now know that the world has indeed changed, but not in quite the sense that politicians and commentators envisaged three years ago.
They looked forward to a new crusade, in which the west went forth to vanquish evil, all the stronger because it was confident of its own rightness. Instead, the west - or at least those parts of it most closely associated with the "war on terror": mainly Britain and America - is losing its moral legitimacy. What matters here is not so much the loss of support and sympathy among the Arab masses - who have long had ample reason to be sceptical of western pretensions - but the corroded self-belief of the west itself.
This is not something that becomes immediately evident. No government will fall as a result of the pictures, now emerging at a court martial, of British soldiers abusing Iraqi prisoners. In the same way, no government fell as a result of the Abu Ghraib pictures showing torture by US soldiers - on the contrary, the US president on whose watch these outrages occurred (and who had propagated the view that any resistance must come from murderous supporters of Saddam, or fanatical foreign terrorists who hardly deserved humane treatment) was re-elected. The final admission this month, from the official US survey group, that Saddam held no WMDs, had no workable plans to acquire or produce them, and had rid himself of what he possessed in the early 1990s caused scarcely a political ripple. Nor do the incarceration without trial of terrorist suspects and the appointment of a US attorney general who regards torture as sometimes acceptable and the Geneva Conventions as quaint excite many outside the legal profession and civil liberties groups. The US destruction of Fallujah, which has been compared to the fascist destruction of Guernica in the Spanish civil war, is now yesterday's story. As for the general carnage and anarchy in Iraq - which was largely stable if brutally repressive until the invasion - we just shrug our shoulders.
It will be argued that a society where these matters can be openly acknowledged and debated is infinitely preferable to one where they are systematically hidden from public view. So it is. At least those Britons and Americans alleged to be responsible for prisoner abuse are put on trial. And there are still plenty of regimes in the world that never have their lies exposed. But comforting myths about what western political leaders call "our way of life" are being stripped away. We are not so committed to democratic accountability, the rule of law and the humane treatment of enemies as we thought we were. It is all very well to argue that these subjects preoccupy wet middle-class liberals and unworldly intellectuals, and that the masses take a more robust view, but a society derives its self-image from its natural leaders and opinion-formers.
Once they can no longer articulate its ideals with confidence - when, so to speak, they cannot keep straight faces any more - the ruling order collapses. That was what happened in the Soviet Union: the people who mattered ceased to believe in it, because the disjunction between the ideals of a workers' paradise and the awful reality became unsustainable. Likewise, the British empire - which depended on the myth that it was a civilising influence, bringing justice and prosperity to backward lands - lost its lustre once, as in Kenya and other parts of Africa, it fell back on repression and brutality, including, as we now know, torture, rape and mass executions. The public didn't then know the half of it, but the imperial ruling class did and it found it impossible to sustain a project that led to atrocities so at variance with its self-image.
Events since 2001 have greatly weakened the west, as Osama Bin Laden no doubt hoped, but without his lifting much more than a finger. Paranoia nearly always leads to repression and aggression, and he has succeeded in stoking it to an extent that even the Soviets rarely achieved. He offers no vision of an alternative society that westerners, or for that matter the great mass of Muslims, can find remotely attractive. Yet he has persuaded the west to behave precisely in accordance with his own image of it: decadent, cruel, sexually perverted, untruthful, imperialist, amoral.
The baboon and the drainpipe
The death of the former Chinese Communist Party general secretary Zhao Ziyang recalls an era of more vivid political insult. In the 1967 cultural revolution, Zhao was called "a stinking remnant of the landlord class" before being packed off to a labour camp. One would not wish that fate on the eventual loser of the Downing Street power struggle, but the two men could manage more entertaining dialogue than their limp exchanges of "I can't trust you" and "you won't back me". Adapting classics of the past (the targets were Abraham Lincoln, Neville Chamberlain, Ronald Reagan and Stafford Cripps), they could try the following: "You are a well-meaning baboon." "You look at foreign affairs through the wrong end of a municipal drainpipe." "You are a triumph of the embalmer's art." [Speaker storms off.] "There, but for the grace of God, goes God." Readers can decide which man should speak which lines.