Drawing on his own early Japanese ties, on newly-opened government archives and recent scholarship, University of Chicago historian Iriye importantly recasts the Pacific War--from a clash of opposites to a power conflict, primarily, between two nations that had more in common than either was originally aware. The story--or parallel history--begins in 1939-40 with Hitler's blitzkrieg and the signing of the Axis Pact: the US must actively support China, now, to weaken Japan as an ally of Germany--and, above all, prevent a link-up between a German-dominated Europe and a Japanese-dominated Asia. But as of spring 1941, that support was still erratic, and so was Chinese resistance: neither the traditionalist Chiang nor the revolutionary Mao was ""automatically on the side of the Western powers against Japan."" Then, in June, came the German invasion of Russia. The Japanese, no longer indecisive, moved into Vietnam; the US, in retaliation, stopped the flow of oil and presented the Japanese with a de facto ultimatum: abandon the ""new Asian order,"" return to the internationalist give-and-take of the 1920s, or risk a war with the US. The generals in power, unwilling to go back, instead prepared for Pearl Harbor. But Iriye has here sounded what will be, in extension, the book's major theme: that, come World War II, the Western powers largely reverted to Wilsonian internationalism; that this was a legacy the Japanese shared--and some Japanese elements adhered to; that, as its military prospects dimmed, Japan began to stress inter-Asian cooperation and to treat its puppet regime in China as a partner--even as the Allies were moving in the same direction (by renouncing extra-territoriality, by proclaiming China a Major Power) vis-Ã -vis the Chungking government; that this dual movement ultimately prepared the Japanese to accept defeat on the basis ""that the objectives they had fought for had been achieved."" Further parallels emerge: neither Japan nor the US was able to act effectually in China; neither promoted the independence of colonial peoples. And, for both, Russia was the new unknown quantity. All of this is developed largely from internal communications, in which the attitudes of Japanese moderates, tiptoeing toward peace, and State Department meliorists, planning for peace, are seen to strikingly converge. As of October 1943, one State Department planner was able to accurately identify just those Japanese who would be available to operate a ""reformed,"" postwar government. So it was just a matter of time . . . but--and this is Iriye's great concluding point--too much time: had the Japanese directly approached the Allies, once they had assurance that the Emperor would not be deposed, they would have lost nothing not already conceded and would have spared the world the onset of atomic war. He is not just hypothesizing: the lesson of his unprecedented parallel exposure of the antagonists not-so-different actions and views is, unmistakably, that war is not necessarily inevitable, that surrender is not necessarily capitulation. With much new evidence to augment existing works (too much for some readers, perhaps, on the Japanese occupation of China), a book impressive for its scholarship, its originality, and its deep engagement.