While the use of torture by americans is deplorable, and does and fuel to the fire, I don't think you can blame 9/11, the previous attack on the trade towers, the embassy bombings, and all the other attacks prior to 9/11, on the use of torture, particularly given that countries in the middle east bring torture to a whole new level. In addition, they fundamentalist have no problem killing civilians. Finally, America has not been the only target for terrorist attacks from fundamentalists. I think it has much more to do with america being one of the largest and most interfering capitalist nations, and supporting Israel.
Just my opinion.