The story of 9/11 is filled with painful “what-ifs.” Among the most prominent: What if the CIA hadn’t blocked two FBI agents from alerting Bureau headquarters that a future 9/11 hijacker had obtained a multi-entry U.S. visa? What if the FBI hadn’t nixed agents’ request for a warrant to search the computer of “20th hijacker” Zacharias Moussaoui after his arrest in August 2001? What if the FBI hadn’t ignored a Phoenix agent’s July 2001 recommendation to contact aviation colleges across the country, on suspicion that Osama bin Laden was preparing extremists to “conduct terror activity against...
