If use of nukes, kills indiscriminately both combatants & civilians ,how can their use be morally justified?

the fully-worded Q ,from my serial Q's on the moralty of using nukes and other WPM's, is this: If use of nukes, kills indiscriminately both combatants & civilians( who may be vics of that military ) ,how can their use ever be morally justified?( IMO, I do not believe, Make no mistake, that the ends don't justify the use of immoral means and expediency or numbers saved vs killed alone or together cannot be a moral argument!) I say this not to A my own Q, but to provide background to why I asked the Q. I hope nobody seeks my Q's deletion bec of it, otherwise the kinds of topics we can Q, will have to be cut-and-dried and irrelevant to real life!