The contributions to this volume provide a birds-eye view on some fundamental elements of international law from the perspective of economics. International law lagged behind compared to other areas of law in benefiting from the influence of economic analysis of law. As Parisi and Pi (Chapter 4) point out, one possible explanation for the delayed attention of law and economics scholars to international law is given by the fact that international law was perceived to be governed by informal rules and enforcement mechanisms that resisted formal economic analysis. This volume will hopefully reveal that, contrary to this perception, economics can also successfully illuminate the understanding of informal mechanisms such as those of international law. In this vein, this volume aims at providing a pathfinder through the recent literature and, in pushing the economic understanding of international law, identifying new areas and issues for research in international law and economics.