There was something relevant on 60 Minutes last week. They investigated a terrorist attack that took place at a draw Muhammad competition somewhere in Texas.
The FBI had an informant that was gas-lighting this guy to carry out an attack at the event. The informant was in a car behind the perp during the attack. They allowed the perp to begin the attack and open fire on two people. The FBI was basically watching this and allowing the attack to commence, though, it could've easily been prevented.
I imagine 9.11 was essentially the same thing but on a much larger scale. Intelligence agencies were probably aware of the impending attack and were instructed to stand down with plausible deniability.
Are those pics where the cruise-missles hit?