CIA releases declassified files detailing warnings on bin Laden before Sep 11 attacks

Several dozen presidential briefing documents were declassified Friday, the 25th anniversary of the September 11 attacks, detail intelligence government officials had gathered about Osama bin Laden and al-Qaida leading up to the hijackings that killed nearly 3,000 people and upended American national security.

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.

Proclaiming it "an act of exceptional transparency," CIA Director John Ratcliffe said the documents were the agency's single largest release of declassified presidential daily briefs -- the highly classified briefings prepared by the nation's intelligence community for the government's most senior leaders.

The documents range from a February 1998 file -- prepared for then-President Bill Clinton -- titled "Terrorists seeking WMD capability" and mentioning bin Laden and other Islamic extremists to a September 12, 2001, report in which a source indicated the attacks had been planned for two years and had also targeted the US Capitol.

An April 1998 document described the Taliban's unwillingness to hand over bin Laden, at the time seen as their "guest" in Afghanistan, noting their "gratitude for his assistance during the Soviet occupation" was making them "reluctant to alienate him by monitoring or controlling his activities."

Briefers in July 1998 called 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, when a briefer described how conspirators "had evaded security checks during a recent trial run at an unidentified New York airport," and "some members of the Bin Ladin network have received hijack training."

Other documents detail bin Laden's pursuit of materials for making "dirty bombs," conventional weapons infused with radioactive material. By June 1999, according to intelligence officials, his operatives had conducted such experiments with explosives to "increase their energy output." 

About two years before the attacks, intelligence officials were aware bin Laden appeared to be misleading the Taliban about his reluctance to launch an unprovoked attack on the US. Briefs prepared for President George W Bush in early 2001 focused in part on bin Laden's "experimentation by crude means to make and deploy biological agents."

A report a month before the attacks indicated bin Laden's commitment "to conduct terrorist attacks in the US," noting that 1998 al-Qaida attacks on US embassies "demonstrate that he prepares operations years in advance and is not deterred by setbacks."

At that time -- August 2001 -- officials 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 any new ground on the planning of the attacks or on US officials' understanding of how they had unfolded. 

In the years immediately following the attacks, a bipartisan commission highlighted a lack of information sharing among agencies such as the CIA and FBI, and issued recommendations that yielded new positions, including a centralised director of national intelligence, as well as the National Counterterrorism Centre, which analyses domestic and foreign terrorism information across different government branches.

Asked for comment on the release, the White House noted the release of another batch of documents by the National Archives, also Friday. That batch, including interviews with national security officials in the Clinton and Bush administrations, was a product of the commission that probed the attacks from 2002 to 2004.