On June 28, 2001, counterterrorism czar Richard Clarke wrote to National Security Advisor Condoleezza Rice that the pattern of activity suggesting an attack by al Qaeda over the previous six weeks ” ‘had reached a crescendo.’ ” He was convinced that ” ‘a major attack or series of attacks is likely in July.’ One al Qaeda intelligence report warned that something ‘very, very, very, very’ big was about to happen, and most of Bin Ladin’s network was reportedly anticipating the attack. In late June, the CIA ordered all its station chiefs to share information on al Qaeda with their host governments and to push for immediate disruption of cells.”
– 9/11 Commission, The 9/11 Commission Report, Page 257