Attorney General John Ashcroft testified before the 9/11 Commission on April 13, 2004: ” ‘The single greatest structural cause for September 11 was the wall that segregated criminal investigators and intelligence agents. Government erected this wall. Government buttressed this wall. And before September 11, government was blinded by this wall.’ He [also] described how information was not shared within the FBI or between the FBI and other agencies because of these legal restrictions.”
– Thomas Kean and Lee Hamilton, Without Precedent, Page 194