The Cuban missile crises I would say was a lot less precarious than Able Archer or the 1983 Soviet nuclear false alarm alert - which was averted, by, ahem - an engineer!
https://en.wikipedia.org/wiki/1983_Soviet_nuclear_false_alar...
https://en.wikipedia.org/wiki/1983_Soviet_nuclear_false_alar...
His meeting with Cuba in the 90s and the new information presented that McNamara didn’t have during the crisis was especially sobering. McNamara ended the meeting early because he was “unprepared” to learn there were missiles already operational and authorization was already granted to launch if the Cuban build sites were struck.