It's facile to assume a moral equivalence between one side accidentally killing civilians in situations where it's extremely difficult to isolate the enemy, and the other side hijacking jetliners and flying them into office buildings.
The world is more complex than these shallow sides. I wish I could tell you what I see in one comment, but I can't. All I can ask you to do is to read history from a neutral perspective and follow the chain of causality down the ages.
I've read enough to know that I don't understand the world, and I never will. I can merely try to help other human beings unconditionally no matter what. This might sound crazy, but provided that a terrorist is willing to take a path of peace and understanding I am willing to give him/her a peaceful home both mentally and physically.
I wish you peace.
Al-Qaeda are about as Saudi as the IRA is British. The people who make that argument, and forget the close ties between Al-Qaeda and the Taliban in the first place, are the ones who need to read a thing or two on geopolitics.