This paper shows how international law scholarship might adopt a constructivist interdisciplinary research design to better engage with the political and social context of legal rules and institutions. In 2005 the Asia-Pacific Partnership was launched by the United States and Australia as a climate change institution outside the UN climate process. Controversially, the Member States claimed the Asia-Pacific Partnership was complementary to the UN climate process. This paper investigates the veracity of this claim by analysing the normative compatibility of the Partnership and the UN climate process. The paper adopts Dryzek's discourse theory to analyse the shared ideas and assumptions underlying both institutions. This analysis indicates that the Asia-Pacific Partnership embodied a deep market-liberal discourse that is in significant tension with the more interventionist and equity-based principles underpinning the UN climate process. This market-liberal discourse is important for understanding recent developments in global climate governance.