I had never heard of Stanislav Petrov or of this rather crucial event - or non event as it turned out to be. The film is surprisingly engaging when one considers the star - the man himself then in his seventies - a grumpy, weather-beaten ex Lieutenant Colonel in the Soviet army who lives in poverty in a Moscow suburb. Little did we know that, had he not been as cool as a cucumber one night in 1983 when on duty at the Soviet Air Defence, the entire planet could have turned to desert with no life able to survive. It may not have turned out this way but the odds are in its favour sadly. There are lighter moments when he comes to America and asks to meet Kevin Costner,. It transpires that Costner had written to Petrov when he was researching 13 Days. This is a MUST SEE so see it!!!!!!