This paper contributes to recent revisions to the English School (ES) which have sought to redress its Eurocentrism. It argues that, despite providing necessary accounts of non-Western international societies and the agency of non-European polities in the expansion of global international society, there remains a gap in capturing the agency of postcolonial states in contributing to order negotiation and management in contemporary international order. It proposes a social role negotiation framework to address the gap, which it situates within a holistic conceptual framework that supplements an ES understanding of international order between states with a world-system perspective on how states are embedded within global capitalism, and a neo-Gramscian focus on social forces as the key agents contesting and shaping states' foreign policy orientation. It highlights two major types of postcolonial state agency within international order: contesting and limiting great powers' legitimate exercise of power; and establishing responsibilities towards building and managing order vis-a-vis great powers. The paper illustrates the utility of the social roles framework with the example of ASEAN in Southeast Asian and Asia-Pacific order.