Today, the European Union faces challenges that threaten not only internal cohesion but also its position in the global system. This book is about the future of the EU in the light of global power transition taking place in the twenty-first century and demonstrates how its future rests on a delicate balance between policy challenge, member states' interests, and convergence or divergence of societal values across its peoples. The book examines factors behind the decline of the EU relative to the rise of China and other powers in the global hierarchy and what policy options are available for EU leaders to implement in order to compete as a global actor. It analyses determinants of regional integration and key policy challenges the EU faces in its quest for an "ever deeper union," and identifies significant factors (i.e., power relations, economic relations, emergent social values across the EU) that can explain the likelihood of further integration or conflict between EU member states. This text will be essential reading for scholars, students, and practitioners interested in European Union politics international relations, security studies, and comparative politics.