This book is written to explain the reciprocal relationship between Indonesia and ASEAN in terms of fulfilling national and regional interests related to the security and stability of territorial waters in the region. It is hoped that this book can better explain the strength and significance of Indonesia's role in ASEAN and vice versa. The discussion is structured in such a way that readers are invited to understand the maritime security discourse at the regional level, forms of cooperation and ASEAN security interests in the maritime sector, Indonesia's maritime economic interests, strategic issues of crime at sea, Indonesia's maritime diplomacy in ASEAN, and interactions between forces in the Region. The entire discussion is woven with a common thread between the national framework and regional security conditions.