9/11/2001 - W was in front of a joint session of CONGRESS naming names within days of the attack.
Sending troops to Libya would conflict with Obama’s campaign message of “ending wars” and withdrawing troops from around the world. To “win” on this issue, he wanted to avoid deploying troops to Libya AND he needed to make it sound like terrorist groups were weak enough that deploying troops would no longer be necessary around the world. Hence, that leads to the White House trying to spin that this was a “spontaneous” riot which could not have been predicted and has no connection to organized terrorism.