This volume examines the explanatory nesting approach in the analysis of international relations and its continuing relevance in the 21st century. International relations theory urgently needs strategies for coping with the growing complexity of the international system following the collapse of the US-Soviet bipolar stalemate, the multiple challenges to US unipolar hegemony, and the rise of powerful non-Western actors. Over the course of this book, leading scholars of international relations and diplomatic history return to an approach to explanation pioneered in the writings of Robert...