The US government lied
From National Security Advisor Dr. Condoleezza Rice to the President of the United States George W. Bush, a lie was maintained in the wake of the attacks of September 11, 2001 – Nobody in our government could have envisioned using aircraft as weapons to fly into buildings. I wonder if someone’s resignation is in order…
Proof: "Discussed for some 40 years"
Homeland Defense and the Transportation Industry: The Civil Aviation and Surface Transportation Sectors.
In the last meeting (May 2001), participants discussed Washington and New York as the most likely targets, even discussing a scenario in which a plane is hijacked and crashed into a high-value target. In fact, this scenario had been discussed for some 40 years, the supposed target typically a nuclear reactor.Denver Council on Foreign Relations Reports
Proof: NORAD Anticipated and Prepared For Aircraft Event
NORAD had drills of jets as weapons
By Steven Komarow and Tom Squitieri, USA TODAY