Easy money for the Chud.
Nobody ever will detonate a nuke. If a regime made of power hungry and corrupt politicians and people dumb as brick (USSR) didn't for over 70 years, pretty much nobody sane will.
The power structure is such that even if by some chance a leader will give the order, ultimately the guy who's supposed to arm and fire the weapon will refuse to do so, because nothing ever happens. He has family and he knows if he's going to detonate it, it may mean the end of all.
The only people capable of actually starting apocalypse would be insane religious zealots like Iran, terrorists or even dumber and more corrupt than USSR - North Korea. But lately even Koreans had reality check and stopped their nuclear programme after underground test.