LONDON -- The other day Ken Livingstone, the mayor of my hometown of London, organized a conference on Islam and the West. It was a carefully rigged affair in which handpicked speaker after handpicked speaker stood up and announced that the democracies were to blame for the tidal wave of murder sweeping the world. To provide a spurious air of balance, the organizers invited a few people who dissented from the line of the Muslim Brotherhood and its British allies. Agnès Poirier, a French feminist, was one of them, but she pulled out because although there were no special facilities for Christians, Hindus and Jews, Mr. Livingstone had provided separate prayer rooms for Muslim men and Muslim women.

She wanted to know: Does Ken Livingstone's idea of multiculturalism acknowledge and condone segregation? It clearly does, but what made this vignette of ethnic politics in a European city worth noting is that commentators for the BBC and nearly every newspaper here describe Mr. Livingstone as one of the most left-wing politicians in British public life. Hardly any of them notices the weirdness of an apparent socialist pandering to a reactionary strain of Islam, pushing its arguments and accepting its dictates.

Mr. Livingstone's not alone. After suicide bombers massacred Londoners on July 7, 2005, leftish rather than conservative papers held British foreign policy responsible for the slaughters on the transport network. ("Blair's Bombs," ran the headline in my own leftish New Statesman.) In any university, you are more likely to hear campaigns for the rights of Muslim women derided by postmodernists than by crusty conservative dons. Our Stop the War coalition is an alliance of the white far left and the Islamist far right, and George Galloway, its leader, and the first allegedly "far left" MP to be elected to the British parliament in 50 years, is an admirer of Saddam Hussein and Hezbollah.

I could go on with specific examples, but the crucial point is the pervasive European attitude to the Iraq catastrophe. As al Qaeda, the Baathists and Shiite Islamists slaughter thousands, there is virtually no sense that their successes are our defeats. Iraqi socialists and trade unionists I know are close to despair. They turn for support to Europe, the home of liberalism, feminism and socialism, and find that rich democrats, liberals and feminists won't help them or even acknowledge their existence.

There were plenty of leftish people in the 20th century who excused communism, but they could at least say that communism was a left-wing idea. Now overwhelmingly and everywhere you find people who scream their heads off about the smallest sexist or racist remark, yet refuse to confront ultra-reactionary movements that explicitly reject every principle they profess to hold.

Why is the world upside down? In part, it is a measure of President Bush's failure that anti-Americanism has swept out of the intelligentsia and become mainstream in Britain. A country that was once the most pro-American in Western Europe now derides Tony Blair for sticking with the Atlantic alliance. But if Iraq has pummeled Mr. Blair's reputation, it has also shone a very harsh light on the British and European left. No one noticed it when the Berlin Wall came down, but the death of socialism gave people who called themselves "left wing" a paradoxical advantage. They no longer had a practical program they needed to defend and could go along with ultra-right movements that would once have been taboo. In moments of crisis, otherwise sane liberals will turn to these movements and be reassured by the professed leftism of the protest organizers that they are not making a nonsense of their beliefs.

If, that is, they have strong beliefs to abandon. In Europe and North America extreme versions of multiculturalism and identity politics have left a poisonous legacy. Far too many liberal-minded people think that is somehow culturally imperialist to criticize reactionary movements and ideas -- as long as they aren't European or American reactionary movements. This delusion is everywhere. Until very recently our Labour government was allowing its dealings with Britain's Muslim minority to be controlled by an unelected group, the Muslim Council of Britain, which stood for everything social democrats were against. In their desperate attempts to ingratiate themselves, ministers gave its leader a knighthood -- even though he had said that "death was too good" for Salman Rushdie, who happens to be a British citizen as well as a great novelist.

Beyond the contortions and betrayals of liberal and leftish thinking lies a simple emotion that I don't believe Americans take account of: an insidious fear that has produced the ideal conditions for appeasement. Radical Islam does worry Europeans but we are trying to prevent an explosion by going along with Islamist victimhood. We blame ourselves for the Islamist rage, in the hope that our admission of guilt will pacify our enemies. We are scared, but not scared enough to take a stand.

I hope conservative American readers come to Britain. But if you do, expect to find an upside-down world. People who call themselves liberals or leftists will argue with you, and when they have finished you may experience the strange realization that they have become far more reactionary than you have ever been.

Mr. Cohen, a columnist for the Observer and the New Statesman, is the author of "What's Left?: How Liberals Lost Their Way" (Fourth Estate, 2007).