Why do member states of international organisations sometimes support the admission of strategic rivals? While existing research emphasises alignment as a key condition for international organisation expansion, it overlooks why members choose to admit certain adversaries but not others. This article examines the case of the Shanghai Cooperation Organization, focusing on Russia and China’s decision to grant full membership to India – a state often viewed as a geopolitical rival by China. We argue that admitting an adversary can serve as a wedging strategy, aimed at preventing that rival from aligning with other competitors. We test this claim by process-tracing the Shanghai Cooperation Organization’s first expansion, tracking changes in the positions of Russia and China on India’s membership. Drawing on primary and secondary sources, our findings highlight the relevance of state-centred risk management in understanding international organisations’ enlargement in general, and China’s view of India-related security risks in particular.
Chen et al. (Mon,) studied this question.