well, whether 911 was usa gov sponsored, or supported by letting it happen, what i do know is that, that is the one single event our country will forver use as an excuse (or call it reason, whatever) to invade anywhere they see fit to fight the war on 'terrorism'... which can be used to mask the REAL reason we are doing what we are doing.
and from a business standpoint, which is how i see government, as a 'business', i can easily see why invading iraq and afghaniston is both lucrative and beneficial for the usa's bottom dollar and growth / expansion in the future. And one thing that most with knowledge in politics, economy, and history will agree on: without competition, acquisitions and mergers (i.e., WARs), big guys eating up the little guys, etc, etc, a business (country/nation/etc) will not thrive in the marketplace (world as a whole) because survival is all about adaptation, expansion, and evolution. Nature will even show you that nothing lasts forever and whatever has come close to it has undergone a lot of change in order to survive.
For the USA to sustain itself and hold the grips it has, its gotta make some serious moves. And most of them you cant just outright say what they are because it would defeat the purpose of said moves.
just my 2 pennies.