Nukes work great against other nations that have them. Just because they're never used doesn't mean they don't work. If they didn't then the Cuban missile cri

Nukes work great against other nations that have them. Just because they're never used doesn't mean they don't work. If they didn't then the Cuban missile crisis would have just been "the start of WW3". The ability of any nation with nukes to have a good enough shot at inflicting catastrophic damage on any nation that attacks them acts as a great equalizer. Every nuclear nation is a nation that nobody else is going to pick a serious fight with with the possible exception of massive deficits in military power (nukes or not if NK levels Seoul for whatever reason the US and China will probably send in troops to calm things down). Uncomfortable peace is still better than war.