A good documentary about a well-known historical epoch reaffirms what we knew. A great one reaffirms what we knew but, through relentless and surprising detail, makes the history new and relevant. The U.S. and the Holocaust , the new three-part documentary from Ken Burns, Lynn Novick, and Sarah Botstein, makes the story of American reluctance to help the Jews bracingly new—and chillingly relevant. The film, which debuts Sunday night on PBS, was born as part of a joint project with the United States Holocaust Memorial Museum. It gives not only an honest assessment of the ways that President Franklin D....