That line of logic really doesn't make any sense at all. I personally believe Bush to be a moron, but he wasn't the only person doing stuff in that administration. Every president, great or terrible, has relied on staff below them to assist and advise, and that's not a bad thing.

Hypothetically, if this was a conspiracy, then Bush's involvement would have been at the very most listening to options and then selecting one. For the same reason I can, in the same sentence, say that America invaded Iraq and that Bush isn't a trained soldier.

(For the record I don't believe 9/11 was a conspiracy.)