ABSTRACT
Over the past few decades, a divide has grown between scholars who build and refine theory, and those who try to explain real-world foreign policy outcomes. In an effort to break this trend, the authors of the preceding essays use and, when necessary, modify international relations (IR) theory to explain a topic that is both ongoing and important. When this endeavour first began, there was very little theoretical work on the enlargement of the North Atlantic Treaty Organization (NATO). When IR theory was applied, it was largely done so for the purposes of evaluating the pros and cons of enlargement, or for explaining how a particular country came to hold its policy position on enlargement.2 The essays in this volume, therefore, represent some of the first efforts directly to ask and answer the question, why is NATO enlarging?
