In the aftermath of the attacks, government agencies realized that they had collected information about the September 11 attacks but, due to interagency rivalries and bureau cratic infighting, had failed to share the information. Thus, the importance of the clues went unrealized. The FBI learned in July 2001 that bin Laden's al-Qaeda organization was planning a massive attack against the United States, but there were few details. Also in July, an FBI agent in Phoenix suggested that the agency look into the possibility that Islamic terrorists were studying at U.S. flight schools to learn how to hijack American planes. In addition, the National Security Agency intercepted a phone call on September 10, 2001, in which the speaker said in Arabic "Tomorrow is zero hour." Unfortunately, the message was not translated from Arabic until September 12. Despite the fact that President George W. Bush was warned by the...