There is absolutely plenty of blame to go around....from Carter's response to the Iran embassy takeover and Reagan's response to the Beiurt marine barracks bombing through Clinton's response following the first WTC bombing.
Why do I hold Bush most accountable. IT HAPPENED ON HIS WATCH and he IGNORED all warnings and recommendations from Clinton's administration regarding the al Queda threat.
I know you dont want links, but look at the urgency in the de-classified memo from the Clinton admin.on Jan 25 2001, only days after Bush took office:
http://www2.gwu.edu/~nsarchiv/NSAEBB...B147/index.htm
And if you look bacK at Bush's foreign policy/national security priorities for the next 9 months leading up to 9/11, THE focus was missile defense, NOT terrorism.
Terrorism in general and al Queda in particular were back burner issue, even with the warnings from Clinton admin. In fact, Condi, as National Security Advisor, was scheduled to give a major foreign policy speech on national priorities on Sept. 12....the focus again was missle defense, with a nod to UN reform. No mention of terrorism. (all records of the speech have since disappeared from the net)