What challenges and risks do Chinese and Russian bases pose to the United States' military strategy? How do the military postures of great powers interact and with what consequences for regional and global security? This book examines the emerging dynamics of geostrategic competition for overseas military bases and base access. The comparative framework adopted in this volume examines how the geopolitical interests of the United States, China, and Russia and their respective underlying force posture interact in different regions including the Indo-Pacific, Europe, sub-Sahara Africa, the Indian Ocean, the Middle East, and the Arctic Circle. By exploring the security, political economic, and domestic political dynamics of specific regions, the contributors to this volume reveal varied motivations for overseas military bases and base access among great powers. With analysis on the particular dynamics of overseas bases in major regional theaters, the book offers a valuable window into the nature and scope of the broader "great power competition" underway in the twenty-first century.