The title belies the author's largely realized goal of providing a critical analysis of Sino-American relations from the 1930's to the present day. Ever-prolific Hoyt uses the entry of the People's Republic of China into the Korean War on October 25, 1950, as the centerpiece of his generation-spanning inquiry. He starts, though, with an evaluation of America's varying China policies before, during, and immediately after WW II. By the author's tellingly detailed account, kneejerk anti-Communism dominated US attitudes toward China following V-J Day. Without lines of communication between Beijing and Washington, he recounts, Zhou Enlai's warning (sent via the Indian embassy) that China would join the Korean conflict if UN forces crossed the 38th parallel fell on deaf ears. And even after Chinese troops went into combat, blunting Gen. MacArthur's push to the Yalu River, the UN command underestimated both the scale and the significance of the intervention. At any rate, the interlopers utterly routed their adversaries, driving them back down the peninsula. By the spring of 1951, however, better-equipped UN forces regrouped and counterattacked; the overextended liberation army (which, despite appalling casualties, had become as unrealistically euphoric as its foe once was) wound up in defensive positions along what eventually became the truce line. In a stinging epilogue, Hoyt reviews more recent events, commending President Bush's measured response to the aging Deng regime's excesses. Time, he concludes, is on the side of those who seek reform of China's sociopolitical institutions. In the author's informed opinion, though, overdue change could have occurred years ago had it not been for the miscalculations leading to the country's involvement in Korea. Diplomatic and military history of a very high order, with a wider-angle focus than Russell Spurr's estimable Enter the Dragon (1988).