New developments in the Asia-Pacific are forcing regional officials to rethink the way they manage security issues. Against this backdrop of regional transition, the contributors to this work explore why some forms of security cooperation and institutionalization in the region have proven more feasible than others, such as bilateral security cooperation and emerging multilateral structures, and factors needed to develop complementary relationships between states. Part I provides an overview of evolving security approaches to the Asia-Pacific region from the Cold War through the current post-9/11 era. The chapters in Part II offer country-based perspectives. Coverage includes the major powers in the region (the United States, China, Australia, and Japan), middle/sub-regional powers (Indonesia, the Philippines, and South Korea), and smaller states (Malaysia, Thailand, and Singapore).