Twenty or 30 years ago, the study of armed conflict was deeply unfashionable among Western scholars. The preference then was for social history and for theory-driven investigations of the past, like “postcolonial studies.” Those intellectual fashions have not disappeared, of course, but over the past two decades, war has invaded the college campus, so to speak. Among the most prolific scholars of military history is Jeremy Black, who has written accounts of 18th-century British grand strategy and World War II, among much else. Now he has taken on…