saying that the US has fault for 9/11 is like saying that a woman with a short skirt is at fault if she is raped.
Actually, that's a pretty good analogy. Nothing justifies rape, even if the girl is wearing a miniskirt and is in your hotel room. But it would be STUPID for a girl to go into a guy's hotel room alone, especially wearing sexy clothes. That's asking for trouble.
So the question is whether anything the US did contributed to the anger in the Muslim world. Nothing justifies taking 2 civilian airliners and crashing them into civilian skyscrapers, but our foreign policies may well have set us up for it.