House of War is a history of intricate and momentous decisions made by powerful and complicated personalities, beginning with the decision that has shadowed and will shadow all subsequent human life: the decision to use the atomic bomb against Japan. Involved in that decision were several others: the decision to demand Japan’s unconditional surrender, the decision whether to publicly demonstrate the bomb’s destructive potential beforehand or to use it first in a surprise attack, and the decision about which cities to put on the target list. Though we all know how these decisions come out, Carroll’s masterly account is freighted not merely with gravity but with touches of genuine suspense. I have not read enough of the large literature on the decision to use the bomb to say with confidence whether his moral judgments about it—and about another profoundly disturbing episode, the firebombing of Japanese cities—are valid. But I can testify that they are plausible, deeply pondered, richly documented, and eloquently stated. It is a new century, but we are not through debating this matter.