As senior al-Qaeda figure Abu Muhammad al-Masri himself said in his book on 9/11 (featuring a length of several hundred pages): these conspiracy theories are themselves promoted by the American and Israeli governments to deter Westerners from purging their governments of Zionist influenced lobbies and elements, and to prevent Muslims people from joining al-Qaeda and not regarding it as that powerful, incredible, capable, and organized of a group. He laments that this seems to have worked, pointing out how many Arabs and Muslims themselves refuse to believe al-Qaeda was behind it, as if they concur with the lamentable stereotype that all Arabs and Muslims are somehow ignorant cave-dwellers and goat herders. The book is titled The September 11 Operations: Between Truth and Skepticism.