In 1968, a loyal officer of the KGB is so shaken by the Soviet invasion of Czechoslovakia that he becomes an operative for British and American intelligence—one, “Spy Wars” reveals (begins Sunday, 8 p.m., Smithsonian Channel), destined to be of historic importance. This is the saga of Oleg Gordievsky—subject of the first episode of this eight-part weekly series, and a rich portrait it is. When his role of many years as a spy for the British and Americans finally becomes known to the Kremlin, quick exfiltration becomes an urgent necessity. His 1985 getaway in the trunk of a car driven by unflappable MI6 agents, who get...