The work of some of the world's leading specialists on the former Soviet Union and on post-Soviet Russian politics is brought together in this volume. The authors discuss the decline and fall of Marxism-Leninism as a ruling ideology in the Soviet Union and its failure to make a significant comeback in post-Soviet Russia. They analyse the rise of liberal and social democratic thought in Russia and examine the conceptual revolution of the Gorbachev era. Particular attention is paid to radically new ideas on the political and economic systems, on foreign policy, and on nationalism, sovereignty and federalism. In chapters that carefully complement each other, the authors make a major contribution to understanding the nature and sources of change in Russia over the past two decades. They not only show how an ideological system was turned on its head in the former USSR but also throw light on the independent role that can be played in politics generally by ideational change.