The challenge for Gorbachev, says Karen Dawisha, is the task of improving the viability and stability of the East European regimes without unleashing societal forces that could threaten the reform movement in both Eastern Europe and the U.S.S.R. In her account Dawisha stresses the realities of Soviet security interests and the history of each East European nation. The subject matter is familiar; the treatment is clear, competent and professional; the conclusions, justifiably, are cloudy. Indeed much depends on Gorbachev, but the issues lie deeper than the fate of his reforms.