I had conducted on a narrower topic—that of ‘self-contained regimes’ in international law. At the time, I was struck by the variety of explanatory ‘narratives’ that sought to make sense of the changing configuration of the international order in the past few decades. Each narrative, detecting different degrees of unity and fragmentation in the international order, seemed pertinent in its own way provided that one accepted its theoretical premises. At the very core of the perceived threat to unity within the international order are international regimes—institutionalized arrangements in different issue areas possessing their own norms and procedures—that may subject states to conflicting expectations of conduct. The phenomenon of regime conflict uniquely lends itself to multifaceted analysis: it is irreducibly philosophical, political, and legal. A main objective of this book is to provide a more nuanced understanding of regime conflict by acknowledging its multidimensional character. The analysis sets the stage for exploring the role that international law can play in managing regime conflict. A difficulty of any long-term writing project is to keep the manuscript current. A first draft of the theoretical sections was prepared as early as 2006 and 2007, and a complete draft was submitted as a doctoral thesis to Munich University in 2011. When I revised the manuscript for publication in 2013, I did my best to incorporate a variety of recent publications addressing both the theory of regime interaction and the case study of trade in cultural products. However, the reader may find that some recent studies are reflected less prominently in the argument of the present book than they would have been, had I had access to them at the time that the first draft was written. Heartfelt thanks go to my teachers of international law—Bruno Simma, Andreas Paulus, and Michael Reisman. All three have influenced my thinking about international law in countless ways. The present book would not have been possible without each of them. I also thank Seyla Benhabib, Pierre-Marie Dupuy, William Eskridge, David Kennedy, and Harold Koh, whose comments at various stages of my research have been very helpful. Pieter Jan Kuijper and Eric White, formerly with the WTO litigation team at the European Commission’s Legal Service, and my former colleagues at Sidley Austin have taught me more about international trade law and WTO dispute settlement than any scholarly treatise could have. Finally, I am indebted to my thesis committee at the University of Munich, in particular Bruno Simma and Christian Walter, and to three extraordinarily diligent external reviewers of Oxford University Press, whose insightful comments have, as I hope, led to significant improvements of the manuscript. It is a privilege to have had the benefit of five detailed academic reviews before going to publication. I gratefully acknowledge the support received from the Bucerius Stiftung and