Well, if it didn't exist someone would have to invent it. ;-) If they did, angry young Muslims would join up. Then it would exist.

Sounds like a self-sustaining system.

I guess the only question is, who invented it? And to what extent is it a real factor in the present political/military situation?

The notion that Al Queda "barely exists at all, except as an idea about cleansing a corrupt world through religious violence" may be correct. Ideas are very powerful things. America has such ideas too. America, since its inception, has assumed that it can cleanse, enlighten, and improve the whole World through a combination of marketing, spreading its social/political institutions far and wide, and using military force when other persuasion fails. That idea was once called "Manifest Destiny". It was also called the Monroe Doctrine. It's an idea that is offensive, of course, to almost anyone BUT an American. ;-)

The Romans had a similar idea. So did the British. Kipling called it "the White Man's Burden". What a smarmy way to justify the hunger for Empire...

The Soviets had a similar idea too. So did the Nazis. So did the Japanese and Mussolini.