This chapter explores how Global South states use international legal proceedings—specifically the advisory proceedings before the International Tribunal for the Law of the Sea (ITLOS) on climate change—as platforms to articulate their foreign legal policy. Drawing from the concept that international law is intertwined with political interests, the study examines the written and oral submissions of Global South states alongside their high-level statements at the UNFCCC COPs. Through categorical analysis, the research identifies two dominant narratives among the Global South: one centred on developmental interests, as seen in the submissions by Brazil, China, India, and Vietnam; and another focused on vulnerabilities, advanced by small island states and African nations. These differences point to a South–South divide in climate legal-political positioning, despite shared historical legacies. The chapter further demonstrates how participation in advisory proceedings, even when jurisdiction is contested, serves as a strategic tool for states to project their international agendas. By positioning legal narratives within a broader political context, this study shows that international courts and tribunals (ICTs) are not neutral spaces, but contested arenas where law and foreign policy intersect.