Several dozen presidential briefing documents, detailing intelligence gathered on Osama bin Laden and al-Qaida before the September 11 attacks, were declassified by the CIA on Friday, the 25th anniversary of the attacks.
The documents illustrate security analysts' tracking of Bin Laden's movements and support system, as well as concerns about possible threats to US targets. They also detail officials' understanding of his network in the United States and other countries, including how his operations were financed.
CIA director John Ratcliffe described the release as "an act of exceptional transparency", stating it was the agency's largest single release of declassified presidential daily briefs. These highly classified briefings are prepared by the nation's intelligence community for senior government leaders.
The documents span from a February 1998 file, prepared for then-president Bill Clinton, titled "Terrorists seeking WMD capability" and mentioning Bin Laden, to a September 12, 2001 report indicating the attacks had been planned for two years and had also targeted the US Capitol.
In July 1998, briefers considered it "plausible that Bin Ladin places a high priority on conducting attacks in the United States" and noted his "interest in conducting attacks with chemical and biological agents". Two months later, a briefer wrote that Bin Laden's "preferred option is to strike the US on its own soil in Washington", and that al-Qaida "may fly an explosive-packed airplane into a US city".
Potential hijackings were also discussed in December 1998, with a briefer describing how conspirators "had evaded security checks during a recent trial run at an unidentified New York airport", and that "some members of the Bin Ladin network have received hijack training".
A report a month before the attacks, in August 2001, indicated Bin Laden's commitment "to conduct terrorist attacks in the US". Officials also wrote of "suspicious activity in this country consistent with preparations for hijackings or other types of attacks, including recent surveillance of federal buildings in New York", adding that the FBI was "conducting approximately 70 full field investigations throughout the US that it considers Bin Ladin-related".
Many of the documents were redacted to conceal sources' names and other identifying information. They did not appear to break new ground on the planning of the attacks or on US officials' understanding of how they had unfolded.