During the past decade, ASEAN has shifted its focus from political and military security to economic co-operation and development. Although this change may ease the integration of the four mainland Southeast Asian nations -- Vietnam, Laos, Myanmar, and Cambodia – into ASEAN, there remain significant challenges to forge a workable and united ten-member ASEAN. This book examines many of the economic, political, and institutional issues confronting the enlarged regional grouping. The volume is organized into three sections based on the perspectives of the region, subregion, and the newer members. It not only addresses ASEAN's enlargement but also contributes to the debate on ASEAN's shifting role in the twenty-first century.