John Keegan's "The Second World War" (1989) is the Apollonian counterpoint to Max Hastings "Inferno" (2011). Mr. Keegan purges much of the blood and guts from the story: The million who died in the siege of Leningrad are a dependent clause. But he delivers a narrative of such intelligence, clarity and grace that the reader leaves the book with an elevated understanding of what happened and why. Mr. Keegan, the author of "The Face of Battle" and other books in the military canon, is superb on the war lords. "Hitler's attitude towards Russia," he observes, ". . . was suffused by ideology drawn from many sources—racial, economic, historical—and fermented by his own rancours and ambitions into a self-intoxicating potency." Contrasting FDR with "the devious, double-dealing and treacherous" Stalin and Churchill, "transparently a patriot, a romantic and an imperialist," Mr. Keegan writes: "Roosevelt had dozens of attitudes and a few deeply held values, which were precisely those of Americans of his class and his time: He believed in human dignity and freedom, in economic opportunity and in political compromise; . . . he had few policies, either for peace or for war, while war itself he found utterly distasteful." An elegant, seamless account of the strategic, military and industrial dimensions of the war, with penetrating analysis of its leading figures.