> Daniel Benjamin and Steven Simon, in their book, The Age of Sacred Terror, argue that the 9/11 terrorist attacks are purely religious. They are seen as "a sacrament ... intended to restore to the universe a moral order that had been corrupted by the enemies of Islam." It is neither political nor strategic but an "act of redemption" meant to "humiliate and slaughter those who defied the hegemony of God."
> Robert Pape identified 315 incidents, all but 14 of which they classified as part of 18 different campaigns. These 18 shared two elements and all but one shared a third:[61] 1) A foreign occupation; 2) by a democracy; 3) of a different religion. Mia Bloom interviewed relatives and acquaintances of suicide terrorists. Her conclusions largely support Pape's, suggesting that it is much more difficult to get people to volunteer for a suicide mission without foreign occupation.[62]
https://en.wikipedia.org/wiki/Motives_for_the_September_11_a...
>Raymond Ibrahim, as a researcher at the Library of Congress, found a significant difference between Al Qaeda's messages in English directed to a Western audience and al Qaeda's Arab messages and documents directed to an Islamic audience. The Western-directed messages listed grievances as grounds for retaliation employing the "language of 'reciprocity.'" Literature for Islamic audiences contained theological motivations bereft of references to the acts of Western nations.
[0]: https://en.wikipedia.org/wiki/Motives_for_the_September_11_a...