International law is a vast subject, and its importance is increasing. It is sufficient to point to the major role of international law in the conflicts and wars that emerged from the 9/11 terrorist attack and in international efforts to address climate change. These are two of the most important issues of our time. "Globalization" has become a cliché, but it is undeniable that interactions among states have increased enormously over the last twenty years, and this has produced urgent questions for international law. This book provides an intellectual framework for thinking about these questions in a rigorous way.