This chapter focuses on the politics of environmental governance at the regional level. The Association of Southeast Asian Nations (ASEAN) policies, activities and its member nations and civil society engagements at ASEAN platforms are evaluated. As part of their rescaling effort to govern borderless threats, ASEAN empowers state entities and non-state capitalist organisations in its regional development programs such as the Mekong River Dam Project while engaging civil society organisations at the regional level in order to widen and deepen its member states power, authority and legitimacy in Southeast Asia. Social conflicts between ASEAN and Southeast Asian states with civil society organisations demonstrate the strategic political dynamics of environmental governance at the regional level in ensuring that ASEAN persists as an authoritarian institution.