The first four volumes of this eight volume set provide comprehensive coverage of the factors that determined the evolution of world system in the twentieth century. Between them they consider the central questions of the period: - Why did the ′long peace′ of the nineteenth century break down so completely between 1914 and 1945? - How and by what means was a new kind of order created between 1947 and 1991? - Why did this apparently durable system fall apart and with what consequences for the next century? With over 80 thematically organized articles selection by Michael Cox, Volumes 1-4 examine the 20th century as a period of unprecedented turbulence, marked by unprecedented global confrontations. Volume One looks at the causes and consequences of the collapse of the balance of power after 1914. Volume Two examines the emergence of the United States and its impact on international politics in a bipolar world. Volume Three consdiers the peaceful conclusion of the Cold War. Volume Four looks at the ways theorists of international relations conceptualized the post-Cold War unipolar `moment′ under conditions of globalization. Together the Volumes combine to provide an unparalleled resource providing broad coverage of the subject with historical depth and contemporary relevance. The SAGE Library of International Relations is a new series of major works that will bring together the most influential and field-defining articles, both classical and contemporary, in a number of key areas of research and inquiry in International Relations. Each multi-volume set will represent a collection of the essential published works collated from the foremost publications in the field by an Editor or Editorial Team of renowned international stature. They will also include a full introduction, presenting a rationale for the selection and mapping out the discipline′s past, present and likely future. This series is designed to be a `gold standard′ for university libraries throughout the world with an interest in World Politics and International Relations.