For decades U.S, foreign policy was focused on battling the menace of Soviet communism; then, seemingly overnight, the implacable foe collapsed. How did this extraordinary event come about? Political psychologist Steven Kull argues that only a revolution in the thinking of the country's top leaders can explain the swiftness and comparative peacefulness of the recent political transformation. His analysis, based on probing interviews with Soviet policymakers and on a careful reading of the public record, reveals the painful process by which they came to accept the failure of Leninism and to forge an alternative ideology dubbed "new thinking." Kull assesses the influence of new thinking and other streams of thought on post-Soviet foreign policy and behavior and describes the new challenges they present to Western nations.