Freshwater is the most valuable and fragile of the earth’s life-supporting substances. Most major rivers, our principal sources of freshwater, cross national boundaries. Their sustainable management is both vital and challenging. Why do efforts to manage international rivers succeed in some cases and fail in others? The author argues that an understanding of the politics of river management is essential. Based on a coherent analytical framework that draws on theories of political economy and international relations, this study systematically compares five cases of international river management. This comparison produces generalizable insights into the determinants of success and failure. It also generates important lessons on how to manage transboundary rivers more effectively. By offering both theoretical insights and practical solutions to international rivers problems, the book appeals to a variety of readers, including students of international politics, practitioners, and those interested in water issues and international environmental problems in general.