The Trump administration has declassified over 100 pages of documents detailing intelligence shared with the Clinton and George W. Bush administrations regarding Al Qaeda's threats in the years leading up to the September 11, 2001 terrorist attacks. The documents, which are primarily excerpts from presidential daily briefs, cover the period from February 1998 to September 2001.
These declassified materials indicate that U.S. intelligence was aware as early as May 1998, during President Bill Clinton's term, that Osama bin Laden was calling for an attack within the United States. One document from July 1998 states, "We have received four reports from highly questionable sources suggesting Usama Bin Ladin is making plans to conduct an attack in the United States." Analysts at the time believed bin Laden might be considering an attack on a shopping mall in Washington D.C. or plotting a kidnapping, though the specific target was redacted.
The first mention of airline hijacking in connection with Al Qaeda plots appears in a December 1998 document. It noted that "Bin Ladin and his allies are preparing for attacks in the US, including an aircraft hijacking to obtain the release" of Sheikh Omar Abdel-Rahman, who was serving a life sentence for his role in the 1993 World Trade Center bombing. The documents also indicated that Al Qaeda operatives had allegedly managed to evade security checks at an unspecified New York airport during a trial run.
Concerns were also raised about bin Laden potentially acquiring a nuclear weapon, possibly from Russia, though intelligence ultimately concluded he did not possess one. However, fears persisted that the Al Qaeda leader could utilize chemical or biological weapons. A February 1999 document warned, "If Bin Ladin succeeded in buying a chemical or biological weapon, his past behavior and statements indicate he would have no reservations about using it and he would begin searching for a suitable target."
During President George W. Bush's administration, a document from August 2001, just a month before the attacks, stated that bin Laden was "Determined To Strike in US." It noted that following U.S. missile strikes on his base in Afghanistan in 1998, bin Laden had told followers of his desire to retaliate in Washington. An FBI investigation at the time suggested "patterns 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."