Southeast Asia is one of the most diverse regions on the planet, and its geopolitical importance is on the rise. While individual states in this part of the world have been strategically significant in the past, Southeast Asia now finds itself thrust into the limelight of international affairs as a result of the competition currently occurring between the US and China. Those developments have placed greater strategic weight and heightened attendant stresses on the Association of Southeast Asian Nations (ASEAN), the principal group representing the 10 countries in the region.

Even as ASEAN’s strategic pertinence steadily increases, the member states of the grouping face a dilemma over collective action that challenges not only perceptions of ASEAN’s efficacy but also the overall security of Southeast Asia. How they and other interested actors—including the People’s Republic of China (PRC), the US, Australia and Japan—choose to act now will shape the region for decades to come.