Moreso perhaps than Cognitive Dissonance

Solomon Asch Conformity Experiments explain public brainwashing

The Asch Experiment shows how people respond to peer pressure. In the case of 9/11 the confederates (actors) are not just strangers as they are in the video above, but well known pillars of society: news broadcasters, The President, Vice President, Secretary of State, most all politicians, preachers, pundits, intelligence agents, law enforcement officers, analyists, etc. They all repeat the same false information and all name the false culprit (Osama Bin Laden) as demonstrated elsewhere on the news tab of this site where Kevin Ryan talks about Jenkins and Bremmer. Please see my post and the links below Ryan's piece.

Asch Experiment
by Martyn Shuttleworth (2008). Last Updated 01 of August 2012.
A series of studies conducted in the 1950s
The Asch Experiment, by Solomon Asch, was a famous experiment, designed to test how peer pressure to conform would influence the judgment and individuality of a test subject.