According to a declassified CIA intelligence report on June 1, 2003: “In our view, the [9/11] hijackers were carefully selected with an eye to their operational and political value. For instance, the large number of Saudi nationals was most likely chosen not only because of the ease with which Saudi nationals could get US visas but also because Bin Ladin could send a message to the Saudi Royal family that he had deep support from the southwestern tribes for his jihad against the United States, according to press reports.”
– CIA, “11 September: The Plot and the Plotters,” (CTC 2003-40044HC, CIA Intelligence Report), The Central Intelligence Agency’s 9/11 File:, The National Security Archive, June 1, 2003