At Grand Central Station in New York, people have erected an informal shrine. On it are photocopied posters of the missing, nearly a year old now. The posters feature happy wedding pictures and cheerful family snapshots.

"Missing: Zhanetta Troy," reads one, which shows a mother and her new baby. "Age: 32. Marsh Inc. 1WTC #98 Fl. Tuesday was her first work day.""Masara SC," reads another. "Fujibank. He usually wears glasses. He wears braces on his teeth for orthopedics [sic]."

A photo of Diarelia Barahona shows her beaming proudly in her graduation cap. "Dondé esta Mama?" the poster says. "Speaking with her mother in Panama, the last thing she said to her mother is, `Mom, have to go things are falling on my head.' "

Not all the victims of 9/11 were New York investment bankers. They were also restaurant workers, dental assistants, computer clerks. Hundreds of them were foreign-born. They were drawn to the United States by the promise of those same twin beacons the terrorists, in less than two hours, reduced to rubble.

"They should get over it," I hear people say. "More people die in wars and famines all the time. A thousand Africans die every week of AIDS. What makes Americans think they're so special?"

The answer is in those homemade posters. America is special. It has built the most equal, tolerant, diverse and fair civilization in history. Now, that civilization is under siege by a strange new kind of enemy - not a nation, but an absolutist ideology, one that does not tolerate tolerance, diversity, dissent, fairness or equality.

There's another point these moral equivocators miss. This was no natural disaster or combat mission. It was a deliberate massacre of innocent people. Like the suicide bombings in Israel, its objectives were not military but symbolic. They were to kill as many people as possible, to make martyrs of the killers, and to show that Western culture could be brought down.

Poverty does not cause terrorism. Fantasy causes terrorism - the fantasy that God justifies the death of infidels, and that he will glorify those who fall in a holy war against them.

Is it possible for entire societies to be caught up in a mass delusion? Clearly, yes. Radical Islamists are a small minority of Islam. But they live in a delusional culture, where even educated people entertain two simultaneous beliefs. They think the Americans got what was coming to them. And they also think Osama bin Laden and Muslims weren't involved.

Instead, they wallow in remarkable conspiracy theories. Bush did it. Or the Jews. Which amounts to the same thing, since it's a given that the Jews run America. Nor can the Arab leaders, those so-called allies of America, control the radicals. Instead, they stoke their paranoia and their delusions with state-sanctioned hate, delivered through the state-controlled media.

After Sept. 11, thinking people in the West launched themselves on a great bout of introspection. What were the root causes? Why did they hate us? Were we in part responsible? Books about Islam became bestsellers. We wrung our hands about a backlash against our Muslim citizens, and gave our kids extra lessons about tolerance.

Meanwhile, thinking people in the Muslim world embarked on a great bout of denial. The best-selling books about the West are Mein Kampf and conspiracy theories about Jews.

The world that nurtured terrorism is a failure in every way imaginable. The wave of democracy that swept Central America, Eastern Europe and East Asia has passed it by. Illiteracy rates are far higher than in countries that are much poorer. Official corruption is a way of life. The rule of law is shaky, the treatment of women odious.

Yet many Muslims cling to their glorious past, when Europeans lived like animals and Islam was the most advanced culture in the world. They have always blamed their misfortunes on a series of outsiders. America is merely the most recent.

Radical ideologies are an escape valve for young and semi-educated men who can't find jobs in their failed economies. And delusion is the refuge of intellectuals who have been sidelined by the accomplishments of the West. Fanaticism and delusion are preferable to humiliation.

How do you combat such pathology? How do you find common ground with university professors who think Jews are worse than Nazis? I don't know, and neither does the West. What I've learned in the past year is that the usual liberal thinking does not apply. Accommodation, negotiation, diplomacy and logic work only when the other side is rational. The delusion of Western intellectuals is to imagine that it is.

That is the lesson of Israel, where nearly a decade of efforts to negotiate with an irrational opponent collapsed in a wave of terrorist attacks. Negotiation doesn't work if your opponent's bottom line is your extinction. "Asking Arafat to give up terrorism is like asking Tiger Woods to give up golf," Bernard Lewis, the West's pre-eminent scholar on the Arab world, told me recently. And imagining that Saddam can be peacefully contained is a far more dangerous delusion than the one we used to hold about Arafat. Arafat, at least, does not have parts for nukes.

America is caught in a foreign-policy quagmire now, no doubt about it. The clarity and purpose of those early days after the attacks have dissolved into a fog. Too bad, because the world needs more America, not less, and sooner, not later. That serious people should debate this is astonishing. Which do you prefer - a culture that glorifies firefighters or one that glorifies suicide bombers?

And if you doubt what the battle's all about, take a trip to Grand Central Station. The answer is right there, in those hopeful faces that came from every corner of the Earth.