Charles Callan Tansill, one of the foremost American diplomatic historians of the twentieth century, argues that FDR wished to involve the United States in the European War that began in September 1939. When he proved unable to do so directly, he determined to provoke Japan into an attack on American territory. Doing so would involve Japan’s Axis allies in war also, and we would thus enter the war through the “back door”. The strategy succeeded, and Tansill maintains that Roosevelt in accord with it welcomed Japan’s attack on Pearl Harbor. The book is based on exhaustive research in the State Department archives.