The word “integration” means different things in different contexts. As this monograph is part of a series entitled Integration through Law: The Role of Law and the Rule of Law in ASEAN Integration (ITL) (see General Editors’ Preface), it examines the extent ASEAN environmental law contributes to ASEAN regional integration as an ASEAN community. ASEAN's historic transition, from an association in 1967 to its development into a community by December 31, 2015, has seen an evolution in various sectors, not least in environment.

The Introduction to the volume sets the scene, providing an overview of ASEAN and its efforts at regionalism. The history of colonization is noted, which explains the strong emphasis on Westphalian concepts of sovereignty and non-interference with domestic affairs. The efforts at regional integration in the context of the environment closely follow the global environmental movement, from the Stockholm Conference in 1972, to the Rio Conference in 1992 and Agenda 21, which prompted ASEAN's Strategic Plan of Action on the Environment and other initiatives. The ASEAN Way, which involves consensus, respect for the principle of sovereignty and non-intervention, and its challenges and evolution in the context of rapid economic and climatic changes and their deleterious impacts on the environment, are the subject of the chapters that follow.

Chapter 1, ASEAN and environmental sustainability, elaborates on the ASEAN vision of “One Caring and Sharing Community,” aspiring toward sustainable development as a common, uniting goal. It examines the difficulties of achieving the five-year plans of action, making the point that the ASEAN Way “makes for informality, quiet diplomacy, face saving and avoidance of legal instruments i.e. hard law.” However, some successes in hard law are mentioned, particularly the coming into effect of the ASEAN Transboundary Haze Agreement, with ratification by Indonesia, the last state to do so.

Chapter 2, Integrating sustainability into ASEAN state practice, discusses the importance of environmental governance and environmental management systems. The study finds that national environmental law regimes and governance are uneven across the ASEAN member states, and considerable capacity building is required. The issue of “integration through law” is examined from two perspectives – institutional integration and integration of laws and policies. It lauds the success in the stewardship of the region's terrestrial biological resources while noting the lack of concerted policies to safeguard marine natural resources.