For most normal countries that aren't engaged in a power struggle against the world order it is probably safest for them if no one else can have them.
The problem with nukes is that any one competent holder of nukes can basically trigger mutually assure destruction, so more actors are likely going to be more dangerous than the danger from the current holders.
The problem with nukes is that any one competent holder of nukes can basically trigger mutually assure destruction, so more actors are likely going to be more dangerous than the danger from the current holders.