INTRODUCTION Normative debates about how states should orient themselves to the international order dominate international legal scholarship. These debates typically presuppose a tension between the normative aspirations of state sovereignty and binding international obligation. (1) Given this shared presupposition, debates about a broad range of topics in international law--including the incorporation of international law, (2) the "democratic deficit" associated with international institutions, (3) and the potential conflicts between constitutional principles and international law (4)--are predicated on questionable empirical assumptions about the nature of the state and its relation to the international order. The terms of these debates thus require systematic reexamination. In this Article, we propose a sociological model of sovereignty that illuminates (1) the ways in which global social constraints empower actors, including states; and (2) the ways in which institutions--including the bundle of rules and legitimated identities associated with state "sovereignty"--constrain actors. Here, we intend only to introduce these ideas by outlining the conceptual framework of the approach, identifying several foundational propositions of the theory, and summarizing existing empirical research supporting these views. This Article is, in this sense, the start of a much larger project.