Russia’s role in world politics has become the object of a spirited debate among policymakers, think-tank analysts, and academics. Much of this debate focuses on one central question: What are the main drivers, or causes, of Moscow’s increasingly proactive and assertive foreign policy? The purpose of this special issue is to address this question by focusing on the interplay of power, ideas, and domestic influences. Our introductory article sets the scene for this analytical endeavor. More specifically, the article has three aims: (1) to review the existing explanations of Moscow’s assertiveness; (2) to discuss the challenges, opportunities, and benefits of employing eclectic approaches in the study of Russian foreign policy; and (3) to outline the contributions of the articles that follow.