While comtemporary history has illustrated the extent to which ethnic tensions are a major source of violent conflict in the world today, scholars and informed observers have been slow to appreciate the value of ethnicity as a tool in understanding the key political developments of recent years. In this book Daniel Patrick Moynihan considers the concept of the self-determination of peoples and discusses major contributions to the subject from Marx, through Wilson and Lenin, to the UN charter. In a critically executed study, he draws upon a rich and diverse fund of historical and contemporary examples to trace the history and illustrate the considerable predictive powers of ethnic studies. He refutes both the liberal melting pot theory and the Marxist prediciton that ethnic differences would give way to an international proletariat. He explores in particular the role played by ethnic diversity in the collapse of the Soviet Union, and argues that the West's inability to grasp the importance of ethnicity was responsible for its failure to anticipate one of the most important events of the 20th century. This study illustrates how an understanding of the concept of ethnicity is critical to our comprehension of the causes of many contemporary conflicts and to our understanding of international politics.