Yes, it could still happen.
Military establishments are supposed to be full of worst-case pessimists. Nuclear warfighting ideas, however, rely on incredibly optimistic assumptions about universal rationality, near-perfect information, accurate perception, the absence of panic, and an orderly ability to control escalation in the midst of chaos. Someone making those assumptions are not the people you want in the Oval Office when “Ruebek” and “Churya” are off their leashes.
Nuclear war, the exchange of nuclear weapons between two or more states in open conflict. It’s unthinkable. It can’t happen.
Of course, nuclear war is extremely unlikely. Although the Bulletin of the Atomic Scientists has placed the hands of its famous clock at five minutes to midnight, that doesn’t mean very much and never has. The fact of the matter is that world nuclear inventories, led by reductions in the United States and Russia, have never been lower, and none of the major powers expects a nuclear conflict in the way they did during the Cold War. To crib a line from Captain Jack Sparrow, however, nuclear war is not impossible, it’s improbable, and a nuclear war could take place in more ways than you might think, sparked by any number of occurrences from a pure accident to an intentional strike.
Recommended: How North Korea Could Start a War
Recommended: This Is What Happens if America Nuked North Korea
Recommended: The Colt Python: The Best Revolver Ever Made?