“In the middle of August [2001], prompted by repeated warnings that al Qaeda was about to strike, CIA director George Tenet ordered investigators to scour their files for any clues to possible upcoming attacks. At that point, the CIA apparently remembered [future 9/11 hijackers Khalid] al-Midhar and [Nawaf] al-Hazmi, and after checking with INS [Immigration and Naturalization Services], learned that both men were already inside the U.S. On August 23 [2001], they finally decided to alert the State Department, Customs, INS, and the FBI, requesting that al-Midhar and al-Hazmi be placed on the terrorist watch list and asking the FBI to track the two men down. Why they waited 17 months to inform the other agencies that al-Hazmi was in the country or that al-Midhar had obtained a multiple-entry visa for the U.S. in 1999 is unclear. The two Saudi terrorists attended flight schools, opened bank accounts and interacted with at least five other hijackers before September 11. FBI officials are convinced that routine surveillance of al-Midhar and al-Hazmi would have exposed the plot had the CIA only shared its intelligence on a timely basis.”
– John Miller, Michael Stone, and Chris Mitchell, The Cell, Page 303