If the Bush administration orchestrated the 9/11 attacks, it would have required that a fairly large number of people (in positions both influential and not) go along with a plan that would necessarily lead to the deaths of thousands --and possibly tens or hundreds of thousands-- of human lives. Depending on which parts you believe (for example, that the towers were rigged to explode) you are claiming that possibly hundreds of everyday people willingly took part in the murder of thousands of people and not a single one has experienced enough remorse to step up and talk. Even in highly-oppressive and secretive governments, there were people who risked (and lost) their lives to publicize the goings-on that they felt were immoral or illegal.
"Well, evolution is a theory. It is also a fact. And facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts. Facts don't go away when scientists debate rival theories to explain them. Einstein's theory of gravitation replaced Newton's in this century, but apples didn't suspend themselves in midair, pending the outcome. And humans evolved from ape- like ancestors whether they did so by Darwin's proposed mechanism or by some other yet to be discovered."
-Stephen Jay Gould
-Stephen Jay Gould