Peace Operations: Terms & Definitions

Dr. Walter Dorn, Professor of Defence Studies,
Canadian Forces College and the Royal Military College of Canada[1]

Brief prepared for the House of Commons Standing Committee on National Defence, 11 May 2018 (pdf


Many terms and concepts exist to label international operations designed to support peace. These include peacekeeping (a more traditional term, which gained popularity in the late 1950s and remains popular and is still used by the UN), peace support (a term adopted by NATO and the Canadian military in late 1990s that includes peacekeeping as a component), and peace operation (the broadest term, which is used by the UN to include both peacekeeping and special political missions[2]; the term was also adopted by the US military).

Other types of operations/activities that can run concurrently or be part of a peace operation include: conflict prevention, humanitarian assistance, peacebuilding, peace enforcement, and peacemaking.

For many of these terms, national militaries and international organizations have developed doctrines to help clarify the concepts and provide robust definitions. Unfortunately, the doctrines of the UN, NATO, Canada and the US differ on these terms and concepts. Fortunately, they differ only in minor ways and are roughly compatible, though the nuances can be important. A list of definitions from the doctrines of these organizations and countries is provided in Annex 1. A caution: the Canadian doctrinal manual on “Peace Support Operations” (PSO) is quite old (2002) and is long overdue for a re-write. Furthermore, NATO has shifted away from the term “Peace Support Operation” and uses the more generic term “Peace Support” efforts or force, with various types of operations included. These types of operations or roles are shown in Figure 1.

Figure 1.
Types of activities and operations designed to support peace (see pdf)
Adapted from Peace Support Training Centre, Canada, EO 401.02.


The term peacemaking in all the doctrines examined herein (UN, NATO, Canada, US) is based on the idea of bringing the conflicting parties to an agreement, e.g., for an immediate ceasefire or a long-term peace agreement. In colloquial language, however, the term is sometimes used to mean action on the opposite side of the force spectrum: using force to impose an agreement, as in the expression: “If peacekeeping does not work, then peacemaking must be used.” But that meaning should be avoided, since it confuses discussion and another term (peace enforcement) conveys a similar meaning of imposing peace.

Peacebuilding is the effort to develop the infrastructure (political, economic and social as well as physical) for a sustainable peace.

The term humanitarian assistance is self-defining. In practice, it means helping people stay alive so that they can one day return to their normal self-reliant lives and societies.

The term peacekeeping is the one that causes the most difficulty. It implies that a ceasefire is established and is usually associated with the military function of observing and reporting or acting as a buffer or separates armed parties. It carries with it the historical baggage of operations that were common during the Cold War: soldiers patrolling buffer zones between two conflicting but stationary forces during a ceasefire, long or short. While such UN operations are still ongoing, only very few new traditional ones have even been created (such as in Ethiopia-Eritrea mission 2000–2008). The United Nations still uses the term peacekeeping at the insistence of the Non-Aligned Movement, but the organization often distinguishes between the traditional operations and the multidimensional peacekeeping (see Annex 1 endnotes). Almost all operations in the new century have been multidimensional. They may include some traditional roles such as cease-fire monitoring and reporting but they also have more ambitious mandates such as security sector reform, disarmament, human rights, humanitarian assistance, and the protection of civilians (POC). They may use armed force at times in defence of the mandate, in addition to self-defence.

When a recalcitrant or non-compliant party continues to violate the terms of a peace agreement or the norms of humanity, despite repeated warnings to stop, then peace enforcement can be taken against the party through coercive, forceful action. But peace enforcement should only be taken by peace operations as a last resort, when other means have failed. There is much academic and practical debate about whether peace enforcement action can still adhere to the three principles of peacekeeping (namely: consent, impartiality and defensive use of force only). I am of the view that operations doing peace enforcement can still adhere to the trinity, just as the police forces nationally (e.g., in Canada) should, in principles, have gained strategic consent (though democracy), act impartiality (no one is above the law) and act primarily in defence of the law, undertaking offensive operations only under extreme circumstances. In “pure” enforcement operations (such as the Korean War or Gulf War I), there is obviously no consent from the punished party but this would not be “peace enforcement” but simply international law “enforcement,” done under Chapter VII of the UN Charter.


Stabilization/stability operations

A final area of frequent confusion is the term “stabilization” or “stability” operation. Many UN peace operations include the word in their names, e.g., the United Nations Multidimensional Integrated Stabilization Mission in Mali (MINUSMA) and similarly for the UN missions in the Central African Republic (MINUSCA) and D.R. Congo (MONUSCO).[3]

The term stabilization operation is currently much used in the Canadian Armed Forces (CAF), though doctrine under this term is not yet available, despite efforts to develop and procure it. The Canadian doctrine on “Peace Support Operations” does not mention “stabilization operations,” though the goal of creating stability is mentioned several times. Surprisingly, the very extensive NATO Glossary of Terms (2017) does not include “stability operations.”

The NATO-led Afghanistan operation is sometimes viewed as having been a “stabilization operation,” though its name was the “International Security Assistance Force.” Its role changed over time from support for the new Afghan government in Kabul (2002–2005), which originally resembled peace operations (but limited to the Kabul area), to one that increasingly involved counter-insurgency (2006–2014) or “COIN” and elements of counter-terrorism, alongside the US-led counter-terrorism “Operation Enduring Freedom” (2001–2014). A peace operation (UN or other) was never tested in Afghanistan because a viable peace process was never adopted by the parties. The United Nations Assistance Mission in Afghanistan (UNAMA) is a Special Political Mission (SPM) that existed alongside ISAF and focused on peacebuilding and diplomatic efforts. But it had very few military personnel (maybe a dozen, who were only in administrative/staff positions). Even now, UNAMA has no forces or military units on the ground. Perhaps in the future, a large peace operation could be deployed, but the troops on the ground should be mainly from Muslim-majority countries, in my opinion, in order to gain greater local acceptance.[4]

The notion of stability operations is compatible with peace operation but stability operations set a much less ambitious goal. Stability can be obtained without addressing the underlying or root causes of conflict. Stability can be achieved without democracy, e.g., by dictatorship, autocracy or imposition. The stability might also be short-lived. The term peace operation is preferred because it includes and extends to efforts to address conflict at a deeper, long-term level. Here peace should be interpreted both as “negative peace”, meaning the absence of violent armed conflict, and “positive peace,” being the presence of harmony, the just rule of law, and democratic rights.



Given the wide range of operational types, my view is that the best term to cover the broad gamut is “peace operation.” The term includes the vital word, peace, which is the objective of such operations. It does not get weighed down in the simplistic argument over whether there is “a peace to keep.” It includes peacekeeping as one of the potential activities, when more traditional activities by military personnel are carried out.

The terms “peacekeeping” and “peacekeeper” are still important, not only because they resonate in the public imagination and because of their easy alliteration, but because they are still part of the lexicon of the major organizations (like the UN and NATO) and major nations (like US, UK and Canada). More importantly, the term peacekeeping suggests an effort to “keep” or preserve whatever level of peace that may exist in the nation or region. The only condition where it would not apply is the case of total war and chaos, where there is absolutely no peace to keep. Peace operations need to expand the level of peace in fragile or conflict-affected areas, whatever it might be, to the level enjoyed by peaceful nations like Canada – and even here a perfect peace has not been attained.

Of course, more important than terminology is the commitment of nations to support the UN with these challenging operations, however they may be labelled, to advance the cause of peace effectively.



Annex 1. Definitions from the doctrine of selected organizations and governments. (French version: pfd)
(Compiled by Walter Dorn and Danielle Stodilka[5])

Humanitarian assistance / operation

Humanitarian assistance: “Material or logistical assistance provided for

humanitarian purposes, typically in response to humanitarian crises. The

primary objective of humanitarian assistance is to save lives, alleviate suffering

and maintain human dignity.”

Humanitarian assistance: “As part of an operation, the use of

available military resources to assist or

complement the efforts of responsible

civil actors in the operational area or

specialized civil humanitarian

organizations in fulfilling their primary

responsibility to alleviate human


Humanitarian operation: “An operation specifically mounted to alleviate human suffering in an area where the civil actors normally responsible for so doing are unable or unwilling adequately to support a population.”

Humanitarian operations involve the use of military resources to assist in the alleviation of human suffering. They may be conducted independently or during a PSO.” (210.1)

Humanitarian Assistance: “refers to

efforts that relieve or reduce human suffering,

disease, hunger, or privation in an impartial manner.

While HA is provided ideally by civilian

organizations without military involvement,

military forces and other security units may be

mandated or tasked to support humanitarian actions.” (p.xiii)


“Measures aimed at reducing the risk of lapsing or relapsing

into conflict, by strengthening national capacities for conflict management,

and laying the foundations for sustainable peace.”

“A peace support effort designed to reduce the risk of relapsing into conflict by addressing the underlying causes of the conflict and the longer-term needs of the people. Note: Peacebuilding requires a long-term commitment and may run concurrently with other types of peace support efforts.” “Peace building involves actions that support political, economic, social and military measures aimed at strengthening political stability.” (206.1) “Stability actions that strengthen and rebuild a society’s institutions, infrastructure, and civic life to avoid a relapse into conflict.”
Peace Enforcement

“Coercive action undertaken with the authorization of the United Nations Security Council to maintain or restore international

peace and security in situations where the Security Council has determined

the existence of a threat to the peace, breach of the peace or act of aggression.”

“A peace support effort designed to end hostilities through the application of a range of coercive measures, including the use of military force. Note: Peace enforcement is likely to be conducted without the strategic consent of some, if not all, of the major conflicting parties.”

Not used. “The term peace enforcement has muddied the understanding of

when the UN actually carries out a pure enforcement action.” (2.a)

“Application of military force, or the threat of its use, normally

pursuant to international authorization, to compel compliance with resolutions or

sanctions designed to maintain or restore peace and order.”

Peacemaking “Action to bring hostile parties to agreement.” “A peace support effort conducted after the initiation of a conflict to secure a ceasefire or peaceful settlement, involving primarily diplomatic action supported, when necessary, by direct or indirect use of military assets.” “The activities conducted after the commencement of a conflict aimed at establishing a cease-fire or a peaceful settlement.” (205.1) “The process of diplomacy, mediation, negotiation, or other forms of peaceful settlements that arranges an end to a dispute and resolves issues that led to it.”
Peace operation(s)

“Field operations deployed to prevent, manage, and/or

resolve violent conflicts or reduce the risk of their recurrence.”

Not in NATO Glossary; see “Peace Support Force” See Peace Support Operation and peacekeeping “Multiagency and multinational crisis response and limited contingency operations involving all instruments of national power with military missions to contain conflict, redress the peace, and shape the environment to support reconciliation and rebuilding and facilitate the transition to legitimate governance.”


Peace Support

Force / Operation (PSO)

Not defined/used

Peace support:

“Efforts conducted impartially to restore or

maintain peace.

Note: Peace support efforts can include

conflict prevention, peacemaking, peace

enforcement, peacekeeping and


Peace support force:

“A military force assigned to a peace

support operation.”

Not defined. See peacekeeping.

“PSOs include conflict prevention, peacemaking, traditional and

complex peacekeeping and peace building. Related operations can be conducted concurrently,

complementary or independently: humanitarian and enforcement operations.” (201.1)

Not defined/used

“Action undertaken to preserve peace, however fragile, where

fighting has been halted and to assist in implementing agreements achieved

by the peacemakers.”

It is divided into traditional peacekeeping and multidimensional peacekeeping, also defined.[7] So is robust peacekeeping.[8]

“A peace support effort designed to assist the implementation of a ceasefire or peace settlement and to help lay the foundations for sustainable peace. Note: Peacekeeping is conducted with the strategic consent of all major conflicting parties.”

No definition provided but breaks down into:

Traditional peacekeeping and Complex peacekeeping.[9]

“Military operations undertaken, with the consent of all major parties to a

dispute, designed to monitor and facilitate implementation of an agreement (cease fire, truce, or other such agreement) and support diplomatic efforts to reach a long-term

political settlement.”

Preventive action/diplomacy

Preventive diplomacy: “Diplomatic efforts to avert disputes arising between

parties from escalating into conflict.”

Conflict Prevention: “A peace support effort to identify and monitor the potential causes of conflict and take timely action to prevent the occurrence, escalation, or resumption of hostilities.”

Conflict prevention involves a range of preventive actions used to monitor and identify causes of conflict and timely action taken to prevent the occurrence, escalation or resumption of hostilities.” (204.1)

Conflict Prevention: “A peace operation employing complementary diplomatic, civil, and, when necessary, military means to monitor and identify the causes of conflict and take timely action to prevent the occurrence, escalation, or resumption of hostilities.”
Doctrine used
(full source references below)
UN, 2008, pp.95-99 NATO, 2017

2002, pp.2-3 to 2-5.

No definitions section. Descriptions given.

US, 2018, GL-3 to GL-5, and xiii.

Note: French definitions can be found in the French versions of the doctrines of Canada, NATO and the UN (see links below), though not for the US doctrine.


Translation of terms (NATO, 2017)

English French
Humanitarian assistance / operation Assistance / opération humanitaire
Peacebuilding Consolidation de la paix
Peace enforcement Imposition de la paix
Peacemaking Rétablissement de la paix
Peace operations Opérations de paix

Peace Support

Peace Support Force

Soutien de la paix

Force de soutien de la paix

Peacekeeping Maintien de la paix
Preventive action/diplomacy Prévention de conflits

Doctrinal Sources Used

Canada: Department of National Defence (DND), "Peace Support Operations," Joint Doctrine Manual, B-GJ-005-307/FP-030, 6 November 2002. (pdf: EnFr)

NATO: North Atlantic Treaty Organization (NATO), "Glossary of Terms and Definitions (English and French)," AAP-06, 2017 (pdf, 2.7 MB); same definitions are also included in “Allied Joint Doctrine for the Military Contribution to Peace Support,” Edition A Version 1, Allied Joint Publication AJP-3.4.1, December 2014.

UN: United Nations (UN), “United Nations Peacekeeping Operations: Principles and Guidelines,” (Capstone doctrine document),, 2008. (pdf, 450 KB, fr: pdf, 529 KB)

US: United States, "Peace Operations," Joint Publication 3-07.3, 1 March 2018 (pdf, PKSOI)


Online terminology databases

Though not consulted for the table in this analysis, these databases can be useful to view how various terms have been defined and used in the past.

Canada: “TERMIUM Plus: The Government of Canada’s terminology and linguistic data bank,”

NATO: “NATO Term: The Official NATO Terminology Database” (En and Fr)

UN: “UNTERM: The United Nations Terminology Database,” (includes both older and newer definitions from many UN documents)





[1] Dr. Dorn teaches the only course on peace operations in Canada offered at the Command and Staff level. DS526 “Peace and Stabilization Operations: An Evolution of Practice” (DS 526) is offered most years at the Canadian Forces College to officers of rank Major to Lieutenant Colonel.

[2] Special Political Missions are smaller UN missions or offices, led by the UN’s Department of Political Affairs, that are primarily involved in political and social discussion or negotiations, and do not typically deploy armed units.

[3] MINUSCA stands for “United Nations Multidimensional Integrated Stabilization Mission in the Central African Republic” and MONUSCO stands for “United Nations Mission for the Stabilization of the Democratic Republic of Congo.”

[4] My proposal for a peacekeeping force in Afghanistan, which I call UNAMA 2, was: A. Walter Dorn, “Give Peacekeeping a Chance in Afghanistan,” Esprit de Corps, Vol. 16, Iss. 11 (Dec 2009), p.12.

[5] Dr. Stodilka is a Senior Fellow at the Canadian International Council. She suggests that the Elsie Initiative on Women in Peace Operations and Canada’s National Action Plan for the Implementation of the United Nations Security Council Resolutions on Women, Peace and Security 2017-2022 would benefit from clarity on terms and definitions similar to those proposed herein.

[6] The new NATO doctrine does not include “Peace Support Operation” as it once did.

[7] “Traditional United Nations Peacekeeping Operations: United Nations peacekeeping operations conducted with the consent of the parties to a conflict, usually States, in which ‘Blue Helmets’ monitor a truce between warring sides while mediators seek a political solution to the underlying conflict.” “Multi-dimensional United Nations Peacekeeping Operations: United Nations peacekeeping operations comprising a mix of military, police and civilian components working together to lay the foundations of a sustainable peace.” (UN, 2008)

[8]Robust Peacekeeping: The use of force by a United Nations peacekeeping operation at the tactical level, with the authorization of the Security Council, to defend its mandate against spoilers whose activities pose a threat to civilians or risk undermining the peace process.”

[9]Traditional peacekeeping operations (TPKO) are characterized by their impartial conduct, the high level of consent of the parties to the dispute and the PKF’s authorization to use force only in self-defence. They are designed to monitor and facilitate implementation of an agreement so that diplomatic negotiations can seek a comprehensive political settlement.” (207.1) “Complex peacekeeping operations (CPKO) are characterized by their impartial conduct, the low or uncertain level of consent of the parties to the dispute and the PKF’s broader authorization to use force. These operations are often initiated after a peace accord has been signed and the parties have consented to the operation.” (208.1) (Canada, 2002)