I like to play the Cold War simulator game - Balance of Power - which recreates the geopolitics of that era. You can play as USA or USSR. The last time I played, as part of my policies, I gave Zimbabwe aid. The Russkies made an objection about this. I stood my ground and the USSR nuked me over such a trivial offence. That was a silly thing for the USSR to have triggered a global apocalypse over, but my point is - during the real Cold War, we were often closer to nuclear war than we thought we were. The publication of civil defence measures in the event of a nuclear war - Protect and Survive - in the 1970s and 1980s show us that our government was taking nuclear war seriously as late as the early 1980s. This list reveals the top five times in which the world came close to nuclear oblivion. It is quite disturbing to read how world leaders thought about the apocalypse and seriously pondered it as a policy.