In a true zero sum situation it would be a sad reality, but not lunacy. How many slight deviations in the space of possibility would've caused global thermonuc

In a true zero sum situation it would be a sad reality, but not lunacy. How many slight deviations in the space of possibility would've caused global thermonuclear war during the Cold War? Could you guarantee ahead of time that it would not occur? You have the benefit of hindsight now.