So what is it? It's Islamist theology. Note this post from Carol Iannone:
Writing in the Chronicle of Higher Education, Raymond Ibrahim, editor of the Al Qaeda Reader,
tells how, in a position at the Library of Congress that gave him
access to much literature in Arabic, he discovered that al Qaeda is not
inspired by anger at Israel, Western imperialism, American foreign
policy, and so forth, as the Left would have it, but by ...Islamic
theology! According to one ex-jihadi:
The main reason why radicals have managed to increase their following is because most Muslim institutions in Britain just don't want to talk about theology. They refuse to broach the difficult and often complex truth that Islam can be interpreted as condoning violence against the unbeliever — and instead repeat the mantra that Islam is peace and hope that all of this debate will go away.
Ibrahim notes that denunciations of the West appear only in al Qaeda propaganda aimed at the West. The exhortations to Muslims are about the war against the infidel and bringing all the earth to Allah. As bin Laden has written:
Allah Almighty's Word to his Prophet recounts in summation the true relationship: "O Prophet! Wage war against the infidels and hypocrites and be ruthless. Their abode is hell — an evil fate!" Such, then, is the basis and foundation of the relationship between the infidel and the Muslim. Battle, animosity, and hatred — directed from the Muslim to the infidel — is the foundation of our religion. And we consider this a justice and kindness to them.