Actor Asymmetries and Sustainable Development Outcomes in Sister City Relationships

Sister City Relationships (SCRs) have become an important instrument of paradiplomacy through which local governments engage in international cooperation to support local development. Yet, despite operating within similar decentralisation frameworks, SCRs produce divergent outcomes, ranging from failure and stagnation to sustained cooperation. Existing studies largely explain these variations through policy change, institutional capacity, and human resources, while the role of asymmetric relations remains underexplored. This study examines Medan’s partnerships with Milwaukee (United States), Gwangju (South Korea), Penang (Malaysia), and Ichikawa (Japan) through a qualitative case study informed by Asymmetry Theory. The findings identify three interrelated dimensions shaping cooperation outcomes: coordination, relational, and collaboration. In the coordination dimension, asymmetries between state and sub-state actors are associated with cooperation failure where hierarchical relations constrain local action. In the relational dimension, asymmetries between sub-state and non-state actors contribute to programme stagnation when local governments fail to accommodate non-state actors’ interests and expectations. By contrast, asymmetries between partner cities within the collaboration dimension can facilitate knowledge transfer, resource complementarity, and capacity building, thereby supporting successful cooperation. The study demonstrates that asymmetric relations are an inherent feature of SCRs and an important explanatory factor in variations in cooperation outcomes. The findings also underscore the relevance of Sustainable Development Goals (SDGs) 11 and 17 by highlighting effective local governance and multi-stakeholder partnerships.