Although its dust jacket is bespeckled with fatuous comments such as "It will leave no reader in doubt that war is indeed about killing," this book is a useful if rambling study of the central act of combat -- inflicting violent death. More restricted in scope than the title suggests (covering only the two world wars and Vietnam, and only the Australian, British, and American militaries), it reflects wide reading in the enormous literature on war, from official psychiatric reports to memoirs and letters. But there is something overblown in the book's chief conclusion: that many soldiers enjoy killing. The Iliad -- or for that matter, the Bible -- taught humanity that lesson quite some time ago. There is little new in much of the discussion, such as the connections drawn between war and sexuality. The author also takes some liberties with traditional scholarship, which will make professional military historians uneasy. For example, she uses S. L. A. Marshall's discredited statistic that fewer than one-quarter of all infantry soldiers fire their weapons in combat, even though a side remark indicates that she knows better. Disregarding the hype, this remains a moderately interesting if gory read, particularly useful on the history of military psychology.