Arguably, we're beating the shit out of the middle east for the same reason we beat the shit out of Japan (and Germany, just for good measure): Because they hit us.

If you let people hit you, people will know that you let people hit you. The same holds, in a much stronger sense, when you move out to conflicts between societies (or, in the same field, corporations) because such organizations -don't- feel even the empathy that humans do, and so habitually assault one another.

Were the wars worth it? Well that just depends on how hostile you think the world is. I'm fairly certain at least those two were/are. You can't turn the other cheek when attacked and maintain a position that keeps every two bit conquerer from seeing you as a likely target.