I've always maintained that it was merely a symptom, not a root cause. Brutal dictators are another manifestation. The root cause is the traditional attitudes that prevail in that part of the world. The grievance fixation, the contempt for logic and facts, the xenophobia, and the amoral familism.
But why shouldn't be aligned with the terror groups that use the religious rhetoric? Hatred makes strange bedfellows, after all. Why, look at all the Western leftists championing their cause. Kind of puts the lie to all those protestations of liberal ideals, doesn't it?