The jihadists know they can never win on the battlefield, but they figure there's an excellent chance they can drag things out until Western civilization collapses in on itself and islam inherits by default.
That's what the war's about, our lack of civilizational confidence and identity.
Notice the reaction of just about every prominent Western leader after 9/11 was to visit a mosque, President Bush did, the prince of Wales did, the prime minister of the United Kingdom did, the prime minister of Canada did. The premier of Ontario didn't, and so 20 muslim community leaders had a big summit to denounce him for failing to visit a mosque.
We know it's not really a 'war on terror.' Nor is it, at heart, a war against islam, or even 'radical islam.' The muslim faith, whatever its merits for the believers, is a problematic business for the rest of us. There are many trouble spots around the world, but as a general rule, it's easy to make an educated guess at one of the participants: muslims vs. Jews in 'Palestine,' muslims vs. Hindus in Kashmir, muslims vs. Christians in Africa, muslims vs. Buddhists in Thailand, muslims vs. Russians in the Caucasus, muslims vs. backpacking tourists in Bali. Like the environmentalists, these guys think globally but act locally.
So the jihadists are for the most part doing no more than giving us a prod in the rear as we sleepwalk to the cliff. When I say 'sleepwalk,' it's not because we're a blasé culture. On the contrary, one of the clearest signs of our decline is the way we expend so much energy worrying about the wrong things...