In 1983, A Soviet ballistics officer (Stanislav Petrov) draws the right conclusion -- that a satellite report indicating incoming U.S. nuclear missiles is, in fact, a false alarm -- thereby avoiding the happening of a potential nuclear disaster.
In fact, initially Petrov was initially praised for his cool head but later came under criticism and was, for a while, made the scapegoat for the false alarm.
Further investigation, however, found that it was due to either geographical issue or technological faults that satellite had picked up the sun's reflection off the cloud tops and somehow interpreted that as a missile launch. Similarly, Cold War is about ideologies where geography also played an important role. Geographically speaking all enemy territories were within range of the new ICBM's which could launch over 3000miles and hit.
Lt. Col. Stanislav Petrov was duty officer at Serpukhov-15, the secret bunker outside Moscow that monitored the Soviet Union's early-warning satellite system, when the alarm bells went off shortly after midnight. One of the satellites signaled Moscow that the United States had launched five ballistic missiles at Russia.
The alarm coincided with the beginning of provocative NATO military exercises and barely three weeks after the Russians shot down a South Korean airliner that had wandered into Soviet air space -If Petrov would have followed up the signal the issue of cold war would have been severe. The US and the Soviet Union never actually fought each other but tensions between the two remained very strong because America is a democracy and the Soviet Union was communist and moreover distrust between them which arouse after the World War II where they have fought against Hitler together.
Petrov has a gut feeling that the signal was a false alarm. For one reason; the report indicated that only five missiles had been fired. Had the United States been launching an actual nuclear attack, he reasoned, ICBMs would be raining down on them. The other reason being in large part to his lack of faith in the Soviet early-warning system, which he subsequently described as "raw." He reported it as a false alarm to his superiors, and hoped to hell he was right. Petrov could have been forgiven for believing the signal was accurate. The electronic maps flashing around him didn't do anything to ease the stress of the moment.
1) - http://www.wired.com/science/discoveries/news/2007/09/dayintech_0926
2) Wikipedia of cold War.