Situations like that require a judgement as to which evil is the lesser. The judgement may be relatively simple (kill a man who is rampaging through a school shooting children) or it may require someone to play God. I asked Keith about whether the evil of dropping two atom bombs on Japanese civilians was the lesser evil than one which had yet to occur. In my view, that was playing God because you were presuming the future occurrence of an evil that might never have happened (and not least because there were alternative ways open that could have threatened the regime in Japan that wouldn't have involved all the carnage). But Keith thinks that killing of that sort isn't covered by commandments. Well I think that an injunction not to kill, or not to murder, whatever slant you want to put on it, that doesn't cover the deliberate immolation of thousands of innocents isn't worth the tablet it's inscribed on.