When do member state withdrawals lead to the death of international organizations?

Recent research has drawn attention to states' backlash against international organizations (IOs), including whether member state withdrawals affect the longevity of IOs. We therefore ask when do member state withdrawals lead to the death of IOs? We are skeptical of a general link between withdrawal and IO death because on average, any one member is not critical for the survival of an IO. Also, withdrawal is often driven by one member state's preferences diverging from remaining members; these remaining states may band together after withdrawal, ensuring or even enhancing the longevity of the IO. Even withdrawal by several states may not contribute to IO death because a smaller group of remaining members may better overcome collective action challenges. Nonetheless, exit by an important member may affect IO survival by removing resources, market power, and guidance. We test these arguments using survival models on an original dataset of withdrawals across 532 IOs from 1909 to 2014/2020 and illustrate the dynamics with case vignettes. The results support our arguments: withdrawals in general do not lead to IO death but the withdrawal of founding members can speed IO death. Interestingly, withdrawal by economically powerful states seems to facilitate IO survival (often through reform and/or re-entry). These findings contribute to a better understanding of the lifecycle of IOs as well as to the resilience and vulnerabilities of international cooperation.