This is battle, not an academic seminar. We in the West have to discredit, delegitimize and dismantle barbaric ideas.

If you want to understand what motivates suicide bombers, watch the recent movie "Downfall." Based on eyewitness accounts, it chronicles the final days inside Hitler's bunker. In a particularly harrowing scene, Joseph Goebbels and his wife are given the opportunity to have their six young children flee to safety. But Magda Goebbels refuses and instead drugs the kids to sleep. Then she inserts a cyanide capsule into each child's mouth and presses the jaws until the capsule breaks. When explaining why she won't allow her kids to escape, Mrs. Goebbels explains, "I can't bear to think of them growing up in a world without national socialism."

This is the power of ideology. Magda Goebbels had embraced a horrific world view that made her believe that murdering her children was a noble act.

Like all ideologies, radical Islam is a phenomenon of the educated class. From Muhammad Atta to Mohammed Sidique Khan, almost all suicide bombers have been men who read and write.

Nor can foreign policy really explain such rage. The invasion of Iraq clearly has greatly enraged many Muslims, radicalizing some deeply. But can a disagreement over foreign policy really make a Briton like Germaine Lindsay, who had never even visited Iraq, kiss his pregnant wife and child goodbye and go out and blow himself and others up? There is something deeper at work here.

...for Muslims, it is a violent interpretation of Islamic fundamentalism. Born in the Middle East, it has spread like a virus across the Muslim world and into the Islamic diaspora in the West.

The good news is that in the heart of the Muslim world, this ideology is not doing so well. The bombings, increasingly of civilians, are showing Al Qaeda and its ilk in their true light. Arabs are finally denouncing terrorism and also the ideologies that feed it. They need to do much more, and far more forcefully. It's a cliché, but true, that ultimately only Muslims can win this fight.

But Western countries can do more as well. We're fighting a military battle against a phenomenon that is largely nonmilitary.

The director-general of Al Arabiya TV, Abdul Rahman Al-Rashed, asked two weeks ago in the London-based daily Asharq Al-Awsat, "Why would Britain grant asylum to Arabs who have been convicted of political crimes or religious extremism, or even sentenced to death? Not only were they admitted to this country, but they were also provided with accommodation, a monthly salary, and free legal advice... for those who want to prosecute the British government." Recall that bin Laden's original declaration of war against the West was published in only one venue, a London-based newspaper. Next time, let him publish it in Saudi Arabia if he can.

"Extremism, like many other diseases, is an infectious one," Al-Rashed continued. "A small dose of carriers can spread the infection like wildfire, establishing a community full of destructive thoughts and practices." It isn't the only answer, but let's start by making life as difficult as possible for the carriers of this virus.