The CIA has released a substantial number of declassified documents and intelligence reports highlighting warnings provided to US presidents, including Bill Clinton and George W. Bush, about the threats posed by Osama bin Laden and al-Qaeda prior to the 9/11 attacks. Among the revelations are details about specific threats, including plots to hijack commercial airliners and the use of explosive-packed airplanes. These documents, some kept secret for over 25 years, demonstrate that multiple warnings were issued to U.S. leaders about potential terrorist activities, showing a clear alarm bell that was ostensibly overlooked during the years leading up to the attacks.