Unfortunately the laws of war aren't very helpful. The deaths just have to proportional to the military value of the target.
That's a long way of saying "it depends." Killing 1 civilian might be too many to kill a foot soldier at a Taliban camp in the tribal region of Pakistan. Ten thousand might be fine if it meant saving Afghanistan from Taliban rule, as long as that as low as coalition forces could keep civilian deaths.
That's a long way of saying "it depends." Killing 1 civilian might be too many to kill a foot soldier at a Taliban camp in the tribal region of Pakistan. Ten thousand might be fine if it meant saving Afghanistan from Taliban rule, as long as that as low as coalition forces could keep civilian deaths.