In the field of regional economic arrangements, the Asia-Pacific Economic Cooperation (APEC) forum is becoming the key mechanism for promoting regional dialogue and economic interdependence, with an emphasis on the need for nondiscriminatory trade and liberalization. In any event, Asian economic dynamism and the emergence of regionalism, coupled with the end of the Cold War, have posed serious political, economic, and security challenges to the countries of the Asia-Pacific. This chapter examines the regionalism emerging today both theoretically and empirically, with an eye to economic as well as political-strategic relations. Unlike the regionalism of the 1950s and 1960s, today the world's major economic powers such as the United States and Japan are active participants. Regional economic organizations and agreements expand the economic power of the member economies comprising the region and enhance the international competitiveness of regional industries through efficient combinations of economic resources.