---
title: "UN Security Council Reform: Expansion & Veto"
description: "UN Security Council reform aims to expand membership and limit veto power, impacting global governance and influencing Model UN discussions."
url: "https://modeldiplomat.com/learn/glossary/unsc-reform"
---

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Model Diplomat Research Team · Last reviewed June 22, 2026

TL;DR

- UN Security Council reform refers to proposals to expand membership, restrict the veto, and revise working methods of the Council to reflect contemporary geopolitical realities.
- Why has UN Security Council reform stalled for decades?
- What is the difference between the G4 and Uniting for Consensus positions?
- Has the Security Council ever actually been enlarged?
- What does the Ezulwini Consensus demand for Africa?

[Civil Service & Diplomatic Exams](https://modeldiplomat.com/learn/civil-services/glossary)Updated June 22, 2026

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## Positions at a glance

### Supporters

Beyond enlargement and the veto, reform encompasses the Council's working methods—the rules governing transparency, penholdership, and consultation with troop-contributing countries and affected states. These are addressed through Note 507 of the Council President, periodically updated, and championed by the ACT group (Accountability, Coherence, Transparency). A distinct strand is veto restraint: the French–Mexican initiative of 2013–2015 proposes that the P5 voluntarily refrain from using the veto in situations of mass atrocity, and the ACT group's Code of Conduct commits signatories to support credible action against genocide, crimes against humanity, and war crimes. Neither requires a Charter amendment, making them politically lighter but legally non-binding.

### Opponents

Procedurally, reform is pursued through the General Assembly rather than the Council itself. Since 1993 the principal vehicle was the Open-ended Working Group on Security Council reform, which produced extensive debate but no negotiated text. In 2008 the membership agreed to shift to Intergovernmental Negotiations (IGN), conducted in informal plenary of the General Assembly and structured around five clusters: categories of membership, the question of the veto, regional representation, the size of an enlarged Council and its working methods, and the relationship between the Council and the Assembly. The IGN operates by consensus and, unusually, has resisted producing a single rolling negotiating text—a procedural choice that critics argue is engineered to forestall any vote that might force commitments.

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In September 2024, U.S. Ambassador Linda Thomas-Greenfield announced Washington's support for two permanent African seats on the Security Council and a rotating seat for small island developing states.

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