There isn't a simple answer. The history of nuclear weapons is littered with near misses. The number is staggering! If I am to infer a reason for the lack of o

There isn't a simple answer. The history of nuclear weapons is littered with near misses. The number is staggering! If I am to infer a reason for the lack of our destruction I can think of three things that seem invariant from history. 1) we've been really lucky 2) we've been lucky because nuclear weapons are extremely difficult to detonate 3) it would seem that the raw power of nuclear weapons paradoxically has a sobering effect on those who wield them. In that no one who has them seems to actually want to use them this especially goes for those in the command chain responsible for firing them. Not to say at times there haven't been people who would or want to use them, just that nobody yet has.