In 1943, Draper was inducted into the U.S. Army and was thereby "saved from thinking any more about American Communism, at least for the next three years." Draper was put to work in the Historical Section of the 84th Infantry Division, ultimately writing the Division's official history of its activities during the Battle of the Ardennes in World War II. In 1944 Draper also saw the publication at last of a book on French affairs, when mainstream publisher The Viking Press released a book by Draper called "The Six Weeks' War." Draper's transition from a political journalist to a historian had begun.