That's a big part of Command and Control, the farther back in time you go, the greater the likelihood the design of the warhead was not one point safe and it wa

That's a big part of Command and Control, the farther back in time you go, the greater the likelihood the design of the warhead was not one point safe and it wasn't at all assured that it'd take careful triggering to get a full or partial nuclear explosion. A decent chunk of later nuclear tests were to help make bombs one point safe. But even then, it there were absolutely rudimentary fail safes that basically worked on the honor system, for well over a decade. Anyway you still have a mess on your hand if the explosives detonate but there's no chain reaction.