Why were no fighter jets scrambled on 9/11?

The lack of military response to the September 11th, 2001 attacks on the World Trade Center and the Pentagon has been the subject of much criticism and speculation. According to the 9/11 Commission Report, the North American Aerospace Defense Command (NORAD) had protocols in place for responding to hijacked aircraft, but the response on September 11th was slower than it had been in previous cases of hijackings. This was due to several factors, including the sheer number of hijackings that occurred simultaneously, the lack of clear communication between various military and civilian agencies, and the difficulty of distinguishing between actual hijackings and false reports. In the aftermath of the attacks, changes were made to the protocols for responding to hijackings in order to improve the speed and effectiveness of future responses.