@Phaedrus
Luckily due to MAD, the game theory is against any rational actor ever actually using nuclear weapons. Just the risk of escalation has dwindled conflict between superpowers down to nearly nothing, significantly reducing the risk of a World War.
On top of this, a massive number of safeguards have been put in place since and because of all those near-misses.
Humanity's capacity for global annihilation does make our extinction on this planet inevitable on a long enough timeframe, but I disagree that we are closer or as close to that than the first Cold War.