A new documentary film, 'Riefenstahl,' explores the Nazi beliefs of German director Leni Riefenstahl, who directed influential movies that served as propaganda for the Third Reich. The film uses recordings and letters from Riefenstahl's estate to argue that she concealed her support for Nazism. The documentary has prompted a debate in Germany about how to manage her political legacy and whether her postwar rehabilitation was based on false premises. The film has been well received by critics and will be released in the United States next year.