General answers are hard to imagine for the many puzzling questions that are raised by Soviet relations with the world in the early years of the Cold War. Why was Moscow more frightened by the Marshall Plan than the Truman Doctrine? Why would the Soviet Union abandon its closest socialist ally, Yugoslavia, just when the Cold War was getting under way? How could Khrushchev's de-Stalinized domestic and foreign policies at first cause a warming of relations with China, and then lead to the loss of its most important strategic ally? What can explain Stalin's failure to ally with the leaders of...