The Expansion of International Organizations: Insights From the G20’s Inclusion of the African Union

This article explores the expansion of international organizations (IOs) by examining the G20’s decision to grant full membership to the African Union (AU) in September 2023. The AU’s inclusion marks a pivotal moment in global governance, signaling a growing recognition of regional organizations within major international frameworks. The study investigates the driving forces behind such expansions, including geopolitical considerations, economic factors, and normative commitments to greater inclusivity. Additionally, it assesses the impact of expansion on representation, legitimacy, and decision-making within IOs. Using the G20-AU case as a focal point, the article analyzes how power dynamics among global and regional actors influence institutional reform. It evaluates whether expansion strengthens IOs by enhancing greater democratization or rather restores or reinforces the privileged positions of certain club members. The paper conceptualizes IO expansion as a dynamic process influenced by three key dimensions: Structural Incentives, Institutional Adaptation, and Actor-Driven Agency. By analyzing these dimensions, the framework helps explain why and how IOs expand, the implications of expansion, and whether such changes enhance inclusiveness or not.