The United Nations (UN) Security Council is stuck in a peacekeeping trilemma. This is a situation where the Council's three strategic goals for peacekeeping operations - implementing broad mandates, minimizing peacekeeper casualties and maximizing cost-effectiveness - cannot be achieved simultaneously. This trilemma stems from longstanding competing pressures on how the Council designs UN peacekeeping operations as well as political divisions between peacekeeping's three key groups of stakeholders: the states that authorize peacekeeping mandates, those that provide most of the personnel and field capabilities, and those that pay the majority of the bill. Fortunately, the most negative consequences of the trilemma can be mitigated and perhaps even transcended altogether. Mitigation would require the Council to champion and implement four main reforms: improving peacekeeper performance, holding peacekeepers accountable for misdeeds, adopting prioritized and sequenced mandates, and strengthening the financial basis for UN peacekeeping. Transcending the trilemma would require a more fundamental reconfiguration of the key stakeholder groups in order to create much greater unity of effort behind a re-envisaged peacekeeping enterprise. This is highly unlikely in the current international political context.
Williams, P. D. (2020). The Security Council’s peacekeeping trilemma. International Affairs, 96(2), 479–499. https://doi.org/10.1093/ia/iiz199