If the events of 9-11 were truly a surprise to the United States Government then there is no way the Secret Service could have known there wasn't a hijacked or stolen plane heading towards Booker Elementary School that very second.
The Secret Service did nothing. The dog did not bark.
The Secret Service should be in that video, but they are not. It is clear from their inaction that they KNEW FOR A FACT THAT THE PRESIDENT WAS NOT A TARGET OF ONE OF THE HIJACKED PLANES. The intended targets of the planes had to have been known.
The dog did not bark because the criminal was its master.
Quod Erat Demonstradum, the Bush administration was part of the 9-11 plot.