Publication
Peace Missions and Coalition-Formation in the United Nations Security Council
In this article, Madeleine O. Hosli, Gabriela M. G. Bueno and Alexandra Hall analyse how coalitions form in the UN Security Council, focusing on peacekeeping missions and their extensions between 1948 and early 2024.
- Author
- Madeleine Hosli
- Date
- 10 September 2026
- Links
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The research shows that coalition formation in the UNSC differs from traditional theories of government coalition-building. Rather than seeking the smallest possible winning coalition, member states frequently form oversised coalitions. Their decisions are mainly shaped by three factors: national self-interest (Tier I), concerns about their standing and audience costs within the organisation (Tier II), and efforts to protect the legitimacy and credibility of the UNSC (Tier III). National self-interest generally appears to be the strongest driver, while Tier III plays a smaller role in actual coalition formation.
The study particularly highlights the strategic importance of abstentions. Unlike a P5 veto, an abstention allows a resolution to pass while signalling disagreement, enabling states to express opposition without necessarily jeopardising the continuation of a peace mission or their position within the organisation. The analysis also shows that E10 members face greater risks when openly opposing resolutions, making abstention an important tool for balancing national interests with concerns about institutional standing. The 2016 MINURSO extension illustrates how states such as Venezuela and Uruguay could oppose the default coalition when regional and national interests were at stake.
Using voting data and the UNSCRA dataset, the article further demonstrates that coalition formation begins before the actual vote through sponsorship and negotiation processes. Members can join a default coalition, form a dissenting coalition, abstain or vote against a resolution depending on the three Tiers. Shared UN values and collective legitimacy are also frequently used rhetorically to justify decisions that are primarily driven by national interests. Overall, the findings suggest that coalition formation in the UNSC is shaped by a combination of self-interest, institutional reputation, geopolitical dynamics and legitimacy concerns, and that traditional coalition theories therefore need to be adapted to international institutions.