I think I tend to side with CS that it is virtually inconceivable that we would nuke, shall we say Tehran with millions of generally innocent people to chastise a few madmen?
Douglas Hurd eventually came to realise this long after retirement. Would we, if needs be, incinerate the capital of NK with the capital of SK almost within blast range and definitely within the fallout plume?
You need a nice little buffer zone like Poland, Belorussia, and a westerly wind for real deterrence.
A small nuclear CM might be the better way to deliver the bad news.