Regional economic integration consists of agreements among countries in a geographic region to reduce, and ultimately remove, tariff and non-tariff barriers to the free flow of goods, services and factors of production among each other. Since the mid - 1980s East Asia has been experiencing ‘regionalization’ or market-driven integration.

The more prosperous countries of Southeast Asia - Brunei Darussalam, Indonesia, Malaysia, the Philippines, Singapore, and Thailand, referred to as the ASEAN-6 - have moved forward in integrating their economies. The recent admission of the CLMV countries—Cambodia, Lao PDR, Myanmar and Viet Nam - to ASEAN makes the latter a potential force in the global arena. However, it poses new challenges because these economies are new to international trading arrangements and are economically behind the six other members.