I don't think the US government is the total blame here, i do believe there was a terrorist attack, but the US intelligence intercepted it and twisted it into their own plan, instead of telling the American people of the terrorist attack or preventing it, they placed bombs in both towers, and let it go off. So basically we have a terrorist attack the US government knew about, but didn't do anything to prevent for their own good, because notice how the only plane that didn't land anywhere near there target was the one that was mostlikely going to head to the whitehouse.