The deluge of books about Nazi Germany and Adolf Hitler apparently knows no end. In addition to those here under review, dozens of others have appeared in the past two or three years alone, and many more are sure to come. By contrast, scholarly study of Stalinism and the gulag is relatively neglected. As Anne Applebaum observes in Gulag, although "some eighteen million people passed through this massive system," we pay far less attention to Stalin's victims than we do to Hitler's. Many of the millions killed during the Stalin era were simply "driven to a forest at night, lined...