The CIA's top leaders failed to use their available powers, never developed a comprehensive plan to stop al-Qaeda and missed crucial opportunities to thwart two hijackers in the run-up to Sept. 11, the agency's own watchdog concluded in a bruising report.
Completed in June 2005 and kept classified until Tuesday, the 19-page executive summary finds extensive fault with the actions of senior CIA leaders and others beneath them.
"The agency and its officers did not discharge their responsibilities in a satisfactory manner," the CIA inspector general found.
Yet the review team led by Inspector General John Helgerson found neither a "single point of failure nor a silver bullet" that would have stopped the attacks that killed nearly 3,000 people.
In a statement, CIA Director Michael Hayden said the decision to release the report was not his preference, but that he was making it available as required by law.
"I thought the release of this report would distract officers serving their country on the front lines of a global conflict," Hayden said. "It will, at a minimum, consume time and attention revisiting ground that is already well plowed."
The report does cover terrain heavily examined by a congressional inquiry and the Sept. 11 Commission. However, the CIA watchdog's report goes further than previous reviews to examine the personal failings of individuals within the agency.
Providing a glimpse of a series of shortfalls laid out in the longer, still-classified report, the executive summary says that US spy agencies lacked a comprehensive plan to counter Osama bin Laden before Sept. 11.
It also says the CIA's analysis of al-Qaeda before Sept. 2001 was lacking. No comprehensive report focusing on bin Laden was written after 1993.
"A number of important issues were covered insufficiently or not at all," the report found.
"That so many individuals failed to act in this case reflects a systemic breakdown ... Basically, there was no coherent, functioning watch-listing program," the report said.
In a statement, former CIA director George Tenet rebutted part of the criticism.
"There was in fact a robust plan, marked by extraordinary effort and dedication to fighting terrorism, dating back to long before 9/11," he said.