Minilateralism and Backlash in the Nuclear Security Summit: The Consequences of Nuclear Governance outside the IAEA

Abstract Frustration with large multilateral organizations is on the rise, leading some states to seek consensus in exclusive “minilateral” groupings. However, there is little to no research on how such an organization relates to the broader multilateral regime. I use the case of the Nuclear Security Summits (NSS) to examine the consequences of exclusion. I find states excluded from the NSS are more likely to criticize the Summits, even where they share policy preferences with included states. A comparison of follow-on initiatives shows that those more associated with the Summits are less likely to gain support from excluded states in the broader regime and that pushback is directly tied to the exclusion of the NSS. This suggests previously underappreciated costs of minilateral organization and the difficulties that can emerge when minilateral organizations attempt to affect a multilateral regime.