Use of force

The non-use of force except in self-defense and defense of the mandate is one of the three principles of peacekeeping articulated in the 2008 Capstone Doctrine. Self-defense includes the right to protect oneself, other UN personnel, UN property and any other persons under UN protection.

The current guidelines on the use of force entered into effect on 1 February 2017.

Rules of engagement
The circumstances under which a mission may used armed force is spelled out in rules of engagement established for each mission based on its mandate. The rules of engagement will clarify the different levels of force that can be used in various circumstances, how each level of force should be used and any authorizations that may need to be obtained from commanders.

Rules of engagement are developed on the basis of the Guidelines for the Development of Rules of Engagement for the United Nations Peacekeeping Operations, issued in November 2000. These are classified UN Restricted and are not publicly available.

Missions are also bound by the Secretary-General's Bulletin ST/SGB/1999/13 on the observance by United Nations forces of international humanitarian law.

Robust peacekeeping
Recent peacekeeping missions in which the Security Council has authorized the use of "all necessary means" to defend the mandate, including protecting civilians under imminent threat of physical violence, have colloquially been referred to as "robust" mandates. The Capstone Doctrine draws a distinction between robust peacekeeping, in which use of force is applied at the tactical level with the authorization of the Security Council and with the consent of the parties, and peace enforcement, which does not require the consent of the parties and which may involve the use of force at the strategic level

History
The principle of non-use of force except in self-defense dates back to the deployment of the United Nations Emergency Force (UNEF), the first peacekeeping mission deployed with armed peacekeepers, in 1956. UNEF adopted the following approach:

"A reasonable definition seems to have been established in the case of UNEF I, where the rule is applied that men engaged in the operation may never take the initiative in the use of armed force, but are entitled to respond with force to attak with arms, including attempts to use force to make them withdraw from positions which they occupy under orders from the Commander.… The basic element involved is clearly the prohibition against any initiative in the use of armed force."

Subsequently, the concept has expanded to include attempts to prevent the mission to implement its mandate. As noted for UNEF II in 1973,

"The Force will be provided with weapons of a defensive character only. It shall not use force except in self-defense. Self-defense would include resistance to attempts by forceful means to prevent it from discharging its duties under the mandate of the Security Council."