"Lili Marlene," the unlikely anthem of World War II, cut across front lines and ideological divides, uniting soldiers across the globe. This love song, telling the story of a young woman waiting for her lover to return from the battlefield, began as a poem written by a German solider during World War I. The soldier-poet's words found their way to Berlin's decadent cabaret scene in the 1930s, where they were set to music by one of Hitler's favored...