He may have been knee-deep in retirement and dwelling on his legacy at the time, but September 11, 2001 was more than just a terrible day for Bill Clinton as an American. It marked a failure from his administration if you believe the memo that the Central Intelligence Agency put out about the terrorist attacks.
By cutting funds and hampering their powers, the CIA was unable to predict and prevent the attacks according to the memo. They were stretched too thin to be effective according to the document that was dated 2005 from then-Director George J. Tenet.
According to the Washington Times:
The document was a response to an inspector general’s draft report that had accused Mr. Tenet of failing to give al Qaeda enough attention in the months leading up to the Sept. 11 attacks. But Mr. Tenet said he did take steps, amid all the other work CIA was also required to do.