I suppose I should add for most people here: a few nukes aren't a big deal so long as they don't hit high population density area. (Ex: American East Coast.) We've dropped over 2,000 nuclear weapons so far. The biosphere could survive a few more. The main issue is if we are talking about nations like China, Russia, or the United States: Nuclear superpowers wherein disabling their ability to retaliate with extreme force is so miniscule that no sane person would gamble their entire empire on it.