http://www.newrepublic.com/article/world/94546/middle-east-radical-conspiracy-theories: Why Is the Middle East Still in Thrall to 9/11 Conspiracy Theories?
The 9/11 attacks catalyzed a tremendous shift in American foreign policy in the Middle East. Rather than prioritizing petrol, Washington targeted terrorist organizations, dethroned a dictator, and lobbied throughout the region for liberalization. Yet despite the billions of dollars spent policing Baghdad and protecting Benghazi, the unpopularity of the United States in the Arab world continues to be fueled by the belief that Islamist terrorists had nothing to do with 9/11, with many claiming the attacks were an American, Israeli, or joint American-Israeli conspiracy. In this sense, overcoming 9/11 revisionism is, perhaps, the greatest challenge facing American public diplomacy in the coming decade: So long as such conspiracy theories persist, Arabs will continue to view American policies aimed at preventing “another 9/11” as thoroughly illegitimate since, as they see it, 9/11 is just a big American lie.
The answer to the ‘why’ question is that those conspiracy theories point to the truth. The full story, we might suspect, includes possible connections with Saudi Arabia (the spy agencies of Israel, Saudi Arabia, etc, have connections we hardly know about), but the reality that the US false flagged the core conspiracy against 9/11 remains a mystery beyond the capacity of media such as the New Republic.