When David Brooks talks about the narrative that shapes both Islamic extremism and our fear of it, he would do well to consider how deeply rooted this narrative is. Ever since Xerxes and Darius tried to invade Greece around the 4th century B.C., western Europe has been haunted by the fear that a powerful empire from the East would invade and plunge the world into a second darkness. The Movie 300 artfully (and somewhat creepily) connected this story to modern phobias by portraying the Persians as wearing turbans, and the Persian emperor as some sort of bizarre bejeweled half-naked quasi-African tribal chief. It also ignored the fact that life under the Persian empire was arguably closer to modern democracy than the fascistic monarchy of the Spartans. The constant rhetoric about "freedom" from a king who deliberately flouted the rulings of the city council reminded me a lot of George Bush.
After the Persians gave up on trying to conquer Europe, the eastern empire myth was continually reinforced by the fact that 1) Nobody wants to live in the Gobi desert and 2) Anyone who has learned how to survive in the Gobi desert is probably tough enough to grab any piece of real estate they want. Consequently, Europe was perennially threatened by tribes riding forth out of what is now Mongolia and into Europe: The Huns, the Mongols, the Seljuk Turks, the Ottoman Turks. The fact that the Arab Muslims managed to convert the last two groups, and stage an impressive invasion of their own, managed to tie this fear of Easterners to Islamophobia.
The main reason that the Gobi desert warriors were so dangerous is that they were brilliant horsemen. I believe they invented the stirrup, which greatly increased the flexibility of a mounted warrior, and there is lots of documentary footage showing that the Mongols are as good at horseback riding as they ever were. Towards the end of his career, Buffalo Bill added Mongolian horsemen to his Wild West Show, and renamed it "Rough Riders East and West." Now that the horse is essentially useless militarily, the Mongols have become the sweetest, most harmless people you are ever likely to meet. Nevertheless, Orientophobia has been transferred to other targets, and lives on in both literature and foreign policy.
Both Lord of the Rings and the Chronicles of Narnia rely heavily on Orientophobic images derived from medieval epic literature. The human beings who fight for Sauron in the Lord of the Rings have black curly hair, dark skin, gold earrings, and ride on "Oliphaunts". The Orcs and Urukai are patterned after European superstitions about the Mongols, including cannibalism and the use of dragons in battle. The great Calormen empire that lies south of Narnia is inhabited by people who have turbans, scimitars, dark skin, and a poetic speaking style patterned after the Arabian Nights. In The Last Battle, Calormen conquers Narnia, which eventually ushers in Judgment Day. Both authors were temperamentally very tolerant people, and were careful to surgically remove these racist images from their historical context. Tolkien, sensitive to the dangers of racism against actual humans, mentions that the Oliphaunt riders must have been duped or misled by Sauron. (There is no danger of roving bands of skinheads beating up elves.) Tolkien also combined fear of the East with fear of industrial squalor to create a completely new and nonhistorical vision of Imperialistic evil. C.S. Lewis had the Calormens worshiping a god called Tash, who was very like the polytheistic gods that Muhammad was campaigning against.
When the Islamic empires were colonized by the West, the Islamic images of Orientophobia also faded into the background. Nevertheless, politicians and generals where still able to manipulate these fears for rhetorical effect. During World War I, The Germans were referred to as "Huns" (well, Germany is east of France). After World War II, the Communists replaced Islam as the Eastern Bugbear of choice, for it was clearly their intention to conquer the world. Once Communism collapsed, however, there was something even scarier to fear: Nothing. As Heidegger pointed out, Nameless Dread (which he called Angst) is much harder to deal with than any particular enemy. For several years after the Berlin wall fell, the question kept hovering in the background "What do we need all of these weapons for?". The only answer was "Well, the World is a pretty dangerous place."
And then we were rescued from Anxiety, and delivered into Fear, by 9/11. Here was our dear familiar enemy, The Evil Empire from the East, with all of the trappings we had been trained to respond to: The turbans, the beards, the violent attacks, the threat of world domination. The number of people who actually called for the latter was only in the low thousands, possibly even hundreds, but with so much Pavlovian training, the slightest stimulus could trigger a response.