The Central Intelligence Agency has released several dozen declassified presidential briefing documents on the 25th anniversary of the September 11, 2001 attacks, revealing in detail how American intelligence officials tracked Osama bin Laden and his al-Qaeda network in the years leading up to the hijackings that killed nearly 3,000 people. CIA Director John Ratcliffe described the release as "an act of exceptional transparency", calling it the agency's single largest declassification of presidential daily briefs — the highly classified intelligence summaries prepared for the United States government's most senior leaders.

The documents span from February 1998 to the day after the attacks and paint a detailed picture of what analysts knew, or suspected, about bin Laden's intentions. A July 1998 brief judged it "plausible" that bin Laden placed a high priority on striking the United States, and noted his interest in chemical and biological weapons. By September of that year, a briefer wrote that his "preferred option is to strike the US on its own soil in Washington", and that al-Qaeda "may fly an explosive-packed airplane into a US city". Potential hijackings featured again in a December 1998 document 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".

The files also document bin Laden's pursuit of radiological weapons. By June 1999, intelligence officials believed his operatives had conducted experiments with explosives to increase radioactive energy output, in what would have been precursors to so-called "dirty bombs" — conventional devices laced with radioactive material. Separately, briefs prepared for President George W. Bush in early 2001 focused on bin Laden's "experimentation by crude means to make and deploy biological agents". Just a month before the attacks, officials noted "suspicious activity in this country consistent with preparations for hijackings", including surveillance of federal buildings in New York, and said the FBI was running approximately 70 active bin Laden-related field investigations across the United States.

An April 1998 document shed light on the Taliban's protection of bin Laden in Afghanistan, noting that the group's "gratitude for his assistance during the Soviet occupation" — a reference to the 1979–1989 Soviet-Afghan War — made them "reluctant to alienate him by monitoring or controlling his activities". The Taliban had effectively sheltered bin Laden as a "guest", frustrating US efforts to hold him accountable for earlier attacks, including the 1998 bombings of American embassies in East Africa.

Alongside the CIA release, the National Archives published a separate batch of documents on Friday, including interviews with national security officials from both the Clinton and Bush administrations conducted by the bipartisan commission that investigated the attacks between 2002 and 2004. That commission had previously highlighted a critical failure of information-sharing between agencies such as the CIA and the FBI, leading to reforms including the creation of a centralised Director of National Intelligence and the National Counterterrorism Center. While the newly released documents do not appear to break new ground on the planning or execution of the attacks themselves, they underscore how extensively — and how early — US intelligence had identified the threat posed by bin Laden, raising enduring questions about why warnings were not acted upon more decisively.