American scholars tend to write the Civil War as a great national epic, but Keegan (The First World War), an Englishman with a matchless knowledge of comparative military history, approaches it as a choice specimen with fascinating oddities. His more thematic treatment has its shortcomings—his campaign and battle narratives can be cursory and ill-paced—but it pays off in far-ranging discussions of broader features: the North's strategic challenge in trying to subdue a vast Confederacy ringed by formidable natural obstacles and lacking in significant military targets; the importance of generalship; the unusual frequency of bloody yet indecisive battles; and the fierceness with which soldiers fought their countrymen for largely ideological motives. Keegan soars above the conflict to delineate its contours, occasionally swooping low to expand on a telling detail or a moment of valor or pathos. Some of his thoughts, as on the unique femininity of Southern women and how the Civil War stymied socialism in America, are less than cogent. Still, Keegan's elegant prose and breadth of learning make this a stimulating, if idiosyncratic, interpretation of the war.