Exactly. I'm not so sure that every developed country would be brandishing nukes and launching at everyone willy nilly if any of the problem groups were to launch their own payloads, but then again Bisjac probably didn't think too hard before posting
Its nato vs "the other block"
Several nuclear countries would nuke us for using a nuke on n Korea ir anywhere in the world, thus setting off everyone to use em. Thats also why n Korea having them is so bad, because they alone could trigger the use by everyone in an instant.
That is how it works.