You do what you HAVE to do, no more, and you do it with a heavy heart. You do it to prevent more people to suffer, and you do it to make the world of the future a better world than the world of today. You DO NOT do it "to show them", to take revenge, to punish. You DO NOT do it because "they deserve it". That is what these people are doing, and it's not doing any good. It's hard to be good and take responsibility at the same time, but please don't meet evil with evil and call it good, tapping yourselves on your shoulder for being "good guys fighting the evil guys". It ain't that simple. There's too much evil met with evil met with evil met with.... in this world, like some ping-pong game of hatred. Making the "enemies" pure, only black, evil ENEMIES is of course effective to motivate people, like we saw on 9/11 - these people saw the U.S. and probably the whole western world in that simple light. Otherwise they probably couldn't have done what they did. It's harder if you try and see the world in a more realistic way, if you see that your enemies aren't all bad, that you yourself aren't all good, and that there are reasons for what your enemies do and feel. Maybe even something that YOU did/do to them. It's harder to deal with that, so we tend to simplify: "they are evil cowards", period. It's easier to drop a few bombs and kill a few people than to try to make enemies live in peace and accept each other. Of course there might be a need to resort to some violence, but only if you really, really HAVE TO - if you cannot find another way. And there must be a goal of making things better for the future, not just revenge.