This book was originally published in 1974 when there were many theories attempting to explain the problems of international political integration. This book provides a critical analysis of the theories, relating them to relevant hypotheses in politics, economic and sociology. It treats separately functionalism, federalism and contemporary neo-functionalism. The author offers a number of hypotheses which place more stress on the conflicts inherent in late 20^th Century international politics and in the domestic politics of Western European societies. Written for postgraduate and undergraduate alike, any terminology is carefully explained or used in a self-explanatory context