Here is one incident in which the world came very close to a nuclear war. It should be remembered, and Petrov’s name should be honoured:
On 26 September 1983, Lt Col Stanislav Petrov was duty officer at a command centre of a Soviet nuclear early-warning system at a time of serious international tension, when his system reported that one missile had been launched from the United States, followed by up to four more. Although his orders were to report such warnings immediately, Petrov suspected a false alarm, and decided to wait for confirmatory reports, which did not appear. It was subsequently found that the false alarm was from radar reflections from high clouds over North Dakota. Had Petrov passed on the initial false alarm, as per his orders, a nuclear war would probably have followed, and you might not be reading this.
Here is a summary of the times that nuclear deterrence came perilously close to the transition to nuclear war:
A More Peaceful World 