I think it is the Middle East, considering what is going on right now.
My concern (fear) is that someone will think that a suitcase type nuke (say, a fourth the size of the Hiroshima bomb?) will solve some kind of battlefield problem/enemy advance. (Maybe in the Ukraine too?)
Depending on where the bomb is used, there could be a response.
Then most nuclear nations in the world will start thinking, “If I don’t use my weapons now, they will be wiped out before I can.” And they will launch most of what they have.
!!!!!!!!!!