From here [1]
> Petrov was the duty officer at the command center for the Oko nuclear early-warning system when the system reported that a missile had been launched from the United States, followed by up to five more. Petrov judged the reports to be a false alarm,[1] and his decision to disobey orders, against Soviet military protocol,[2] is credited with having prevented an erroneous retaliatory nuclear attack on the United States and its NATO allies that could have resulted in a large-scale nuclear war.
There's a whole list of similar incidents (and I'm pretty sure not all of them have been officially reported). Personally I care more about the feelings of communities that don't bring us one button-push away from annihilating us as a species.