Shaping the Evolution of International Law in View of its Core Effects

Abstract In an international system that is undergoing change, states use international law in a strategic manner. Thereby, they shape the evolution of international law. This article explores how states proceed in this regard. It reviews the role of international law and its strategic use in international politics as well as describes the core effects of international law, namely to constrain, screen, and authorize state behavior. It then examines these effects in terms of the modes that states can use to influence the evolution of international law – agreements and related initiatives, legal positions, state activity, adjudication, and scholarship – and deduces states’ respective strategic options. The article then discusses overarching dynamics and implications for the international legal order. It concludes by arguing that negotiation theory and analysis should give broader attention to the processes that shape the evolution of international law other than by treaty-making.