Crimson Tide (1995) IMDb
Before watching this, read, for example in The Washington Post (2002-10-16), about Vasily Arkhiphov, a sub-brigade deputy commander on a Soviet submarine in the Cuban missile crisis. His sub had a nuclear-tipped torpedo, but not knowing that, the US Navy was dropping depth charges on the sub to force it up. Thinking there was already an apocalyptic war on the surface, the captain of the sub wanted to retaliate with the nuclear weapon, which would have caused WW3. Among the three officers aboard who had a say, Arkhiphov was the only dissenter. He saved quite a few species that day.