Engrossing and skillful account of the Second World War's final month. Ranging from global strategy to unit actions, from high politics to scientific calculation, Weintraub (Arts and Humanities/Penn State Univ.; Long Day's Journey Into War.' December 7, 1941, 1991, etc.) is most satisfying where recent controversies have been most intense. Using the wealth of material that has recently become available, he lays out the uncertainties and fears surrounding the US decision to use atomic bombs on Japan. America had one uranium bomb, never tested. One plutonium bomb could be made immediately but its reliability was unknown; the first and only other device had been fixed in a stationary tower and ignited electrically. In front of the US if it did not use these weapons lay the largest amphibious operation in history, involving 800,000 men, of which the American leadership expected the first echelon to be wiped out. Even after bombs were dropped on Hiroshima and Nagasaki, even with Japan totally beaten, on the brink of famine, and almost unable to muster any defense, Weintraub argues that the decision to surrender was a very close thing. ""Not a single ranking general or admiral in the military hierarchy that ruled Japan would have subscribed to anything resembling capitulation,"" he notes. Young officers tried to frustrate the emperor's decision, and Hirohito's cabinet rejected capitulation. American readers of the Japanese diplomatic code, which had been broken, found nothing in post-Hiroshima communications to confirm that Japan was interested in giving up the war. Weintraub is not sentimental in his judgments, nor does he whitewash the Japanese, whose horrific treatment of POWs included handing them over to universities for vivisection. (For another look at this period, see Thomas B. Allen and Norman Polmar, Code-Name Downfall, p. 597.) A fine book by a historian who has mastered his sources and interweaves his themes with a sure sense of their significance and drama.