First of all, we dont know jack shit about what happened on 9/11.
Second, even if all the media speculation/govt cover up is true, you have to ask yourself what drove those 19 men to cause such disastrous events?
Once you find a logical answer, maybe you will be able to see a connection between the US role in the Middle East in the last 30-50 years and how it came back to bite them in the ass. Im not passing judgement on the policies of the US or the hijackers, i am trying to help you understand THE REASON WHY, not by WHO the acts were committed.