It has long been known that Gabrielle “Coco” Chanel—the legendary French designer whose fashion empire bears her name—was, during the Second World War, the lover of a Nazi officer named Hans Günther von Dincklage. But in “Sleeping with the Enemy: Coco Chanel’s Secret War,” the veteran journalist and investigative reporter Hal Vaughan offers convincing evidence that she was also a Nazi intelligence operative and an incorrigible anti-Semite. Drawing on American, German, French, and British archives, Vaughan reveals that von Dincklage and Chanel—Abwehr Agent 7124 whose code name was “Westminster”—went on missions around Europe to recruit new agents for the Third Reich. And in what is perhaps its most fascinating section, “Sleeping with the Enemy” sheds new light on Chanel’s dealings with the famously tight-lipped Wertheimer family, which purchased a large stake of the business in the nineteen-twenties and controls the entire Chanel empire today. Remarkably enough, the Wertheimers—despite Chanel’s wartime behavior—ultimately decided to finance her reëstablishment in France and eventually agreed to pay her bills for the rest of her life. To this day, the family refuses to discuss Coco Chanel with the media, but Vaughan still manages to paint an engrossing portrait of the dealings between the two. From Paris, Vaughan, who is eighty-two, elaborated on some of the questions his book raises. An edited version of our discussion appears below.