A safer place

I think the thing I really enjoy most about the recent bombing in Pakistan is all the statements about how some people "regret that civilians were killed, but we have to do what we can to take out high-ranking Al Queda members." The apparently logical consequence being that if we don't "take out" the Al Queda members, then they will cause further attacks which will kill civilians. So in other words, we have to kill civilians in order to keep other people from killing civilians.

This whole situation just raises so many questions for me. Would it have been okay to kill 18 innocent people if they had been Americans? What if they were British? How many people is it okay to kill if it means you take out an Al Queda member? What if you think that the person was a member of Al Queda, but it turns out you were mistaken? What if the Pakistani government begins bombing - very specifically, so that they only kill the target and maybe a handful of other people who were in the area at the time - high-ranking member of the CIA, who after all have been responsible for the deaths of innocent Pakistanis? What's ok? How many innocent people is it okay to kill in order to make the world a safer place? And who is the world then safe for?