That's not hyperbole or exaggeration; the events of Sept. 26, 1983, actually nearly caused nuclear war between the United States and the Soviet Union when a faulty Russian detection system erroneously declared that the United States had launched nuclear missiles.
Only the gut feeling of a lone Russian military officer saved the world from probable nuclear holocaust.
Petrov's orders in this case were clear: He was to immediately notify Yuri Andropov, the paranoid leader of the Soviet Union.
Against the backdrop of world events as they were then unfolding, which included the recent Soviet downing of Korean Airlines Flight 007 (which had a United States congressman on board) and NATO's announced decision to move Pershing II missiles into Western Europe in order to increase first-strike capabilities against the USSR, such a notification would have resulted, almost without doubt, in the USSR launching an immediate retaliatory strike against the United States.
With all of this added together, it is almost a certainty that if Petrov had followed orders, nuclear missiles would have been launched at the United States on that day.