Non-use of force is one of the three foundational principles of UN peacekeeping, alongside consent of the parties and impartiality. Together they form what the UN's Capstone Doctrine (formally the United Nations Peacekeeping Operations: Principles and Guidelines, 2008) describes as the bedrock of so-called "traditional" or Chapter VI-style peacekeeping.
The principle traces back to the first armed UN peacekeeping mission, UNEF I (1956), established after the Suez Crisis under the conceptual guidance of Secretary-General Dag Hammarskjöld and Canadian foreign minister Lester B. Pearson. Hammarskjöld articulated that peacekeepers were not combatants and could not impose a settlement; they could only interpose themselves between parties that had consented to their presence.
In practice, the rule has never meant total pacifism. Peacekeepers may use force:
- in self-defence, including defence of UN personnel and property; and
- in defence of the mandate, a broader formulation endorsed by the Capstone Doctrine that permits force to resist attempts to prevent the mission from carrying out tasks set by the Security Council.
The doctrine has been stretched considerably since the 1990s. The failures in Srebrenica (1995) and Rwanda (1994), where peacekeepers stood by during mass atrocities, prompted the Brahimi Report (A/55/305, 2000) to argue that impartiality should not mean neutrality between victim and aggressor. More recent missions have moved further still: the Force Intervention Brigade within MONUSCO in the Democratic Republic of the Congo, authorised by Security Council Resolution 2098 (2013), was explicitly mandated to conduct offensive operations against armed groups — a notable departure from the classical principle.
Debate continues over whether robust peacekeeping and stabilisation mandates, often invoking Chapter VII of the UN Charter, remain compatible with the non-use of force principle or represent a qualitatively different activity closer to peace enforcement.
Example
During UNIFIL's deployment in southern Lebanon, peacekeepers have generally refrained from offensive action, returning fire only when directly attacked, consistent with the non-use of force principle.
Frequently asked questions
Generally no. Force is reserved for self-defence and defence of the mandate, though robust mandates under Chapter VII have authorised pre-emptive or offensive action in specific missions like MONUSCO's Force Intervention Brigade.
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