#9 What are “Rules of Engagement”?

Military Mandates & Instructions for the Use of Force 

– Dr Regeena Kingsley 

The imposition of restrictive rules on armed forces during wartime operations is not a new practice.  Indeed, evidence of their use has been traced back as far as the Middle Ages, enshrined in the royal ‘Letters of Marque and Reprisal’ commissions issued to medieval knights in the fourteenth century, and found within similar commissions and charters given to privateers plundering foreign trade ships in the Elizabethan era of the sixteenth century.[1] 

The concept of Rules of Engagement (ROE) as understood today, however, is said to have originated in the aftermath of the First World War as a reaction to the excess of violence unleashed at certain times on the battlefield during that conflict.  Some have traced their origin to French Prime Minister Georges Clemenceau’s famous proclamation that ‘war is much too serious a matter to be left to military men’, and also to the emphasis placed on ‘the minimum force necessary’ by then Secretary of State for British India, Edwin Montagu, following the Amritsar Massacre in the Punjab during the Indian uprising of 1919.[2]  It was during this post-war era that a general consensus came into being on the part of governments, that the use and degree of force employed by armed forces should no-longer ‘be decided solely by the commanders’. [3] 

Military rules constraining the way in which armed forces employ force during armed conflicts could consequently be said to have developed in conjunction with the growing international consensus in the early-to-mid twentieth century, that war ought to be governed by laws in order to prevent excesses of violence in wartime.  In this sense, ROE have developed as both an operational manifestation and practical interpretation of the Laws of War, most notably the Geneva Conventions of 1929 and 1949 (see endnote for more details).[4]  The term “Rules of Engagement” was not officially used until after the Second World War, however, during the conflicts sparked by the Cold War.[5]

Nowadays it is common practice for a list of ROE to be issued to the senior national military commander prior to deployment on operations, appearing either as an annex within the mandate proper or alongside the mandate as a separate document.[6] 

Rules of Engagement (ROE): A Definition 

Whereas the mandate primarily contains clear instructions regarding the objectives and main tasks of the national contingent, ROE contain precise and classified prescriptions on exactly when (use of force) and how (degree of force) military armed forces may employ force against the Enemy while performing tasks towards stated mission objectives. 

One standard definition, collectively agreed upon and adhered to by NATO since 1973, defines ROE as:

‘Directives issued by competent military authority which specify the circumstances and limitations under which forces will initiate and/or continue combat engagement with other forces encountered’ (see endnote).[7]  

In other words, ROE are the operational expression of the mandate. 

It is precisely for this reason, along with that of protecting deployed military forces (commonly referred to as “force protection”), that ROE are regarded everywhere as classified or “top secret”.  They are guarded jealously by both the military and political institutions of government, and all those with knowledge or access to ROE for a set deployment – current or historic – are often legally prohibited to speak of them in the interest of national security.[8]

Nevertheless, ROE are critical to security operations and can have far-reaching and dramatic consequences, especially within Multinational Operations (MNOs). 

The Mandate Framework Governing MNOs

ROE are located within the national mandate governing the deployment of national armed forces to a MNO.  A mandate is broadly defined as ‘an instruction or command from a higher body that demands compliance’.[9]  A mandate is tantamount to a legal order, often involving a moral obligation too, so that parties in question may only act within the mandate it has received.[10]

In the realm of military operations, mandates can be conceived of as politico-legal instructions that authorise, and conversely constrain, what armed forces may legitimately do when deployed on operations overseas.  As legally-binding documents, deployed armed forces will be held accountable to their mandate under military, domestic and even international law.  Mandates thus form a strong and unbreakable link between the political and military security spheres, whereby armed forces are clearly controlled and restrained in their activities by decisions made by policymakers at the highest political levels.

Mandates are formulated on the basis of political consensus and are issued from the highest legitimate political body within the State at the national level, or within the international community at the international level.  So it is that nationally-elected parliaments and government cabinets issue mandates for national deployments, while the supranational UN organisation issues mandates for multinational deployments in the form of United Nations Security Council (UNSC) Resolutions that are binding on all 192 United Nations (UN) Member-States (see endnote).[11]  NATO and other international organisations, that exist as supranational legal entities and reach decisions on the basis of consensus, may also create and enforce mandates for security operations. NATO’s campaign against Serbia in 1999 is a good example of this, where military action proceeded without reference to, or sanction from, the UNSC.[12]  In order to attain maximum political legitimacy however – where legitimacy refers to the moral authority to exercise power, based on a general belief in the moral rightness or lawfulness of the action – most MNOs involve sanction from both the international organisation in command of the operation and the UNSC, meaning that a multinational campaign may frequently operate under more than one international mandate.[13]  Furthermore, national mandates will also govern the armed forces of all nations making force contributions to the MNO.

Hence, each multinational Peace Support Operation (PSO) will be conducted within a complex and multi-tiered design of moral-politico-legal arrangements, unique to itself, which represent both international and national authority.  For instance, most MNOs operate under mandates issued from: the UNSC at the highest level; the international organisation commanding the operation such as NATO or the African Union at the mid-level; and a range of national mandates issued by the participant nations contributing armed forces to the MNO at the lower levels. In addition, the MNO will also operate under an overarching politico-military treaty, known as a Memorandum of Understanding (MOU) or Military Technical Agreement (MTA), between the Operation Force (e.g. KFOR, ISAF) and the government of the host country where the operation is being conducted, as well as a variety of politico-legal Status of Forces Agreements (SOFAs) between the troop contributing nations themselves and the host government (refer to endnote for more information on the function and content of SOFAs).[14] 

To illustrate this point, consider the range of mandates in place to confer moral, political and legal authority on the current deployment of members of the New Zealand Defence Force (NZDF) to the ISAF operation in Afghanistan, as set forth by the Directorate of Legal Services based at the NZDF’s Headquarters Joint Forces (HQJF) in Wellington.  

Tier 1: At the highest level, a mandate for military intervention in Afghanistan to conduct an international security assistance and stabilisation operation in the wake of Operation Enduring Freedom (OEF) was issued from the UNSC in the form of Resolution 1368 (passed on 12 and 28 September 2001), based on ‘the inherent right of countries to individual and collective self-defence, as recognised by the UN Charter’. [15]  A second mandate specifically authorising the creation of the ISAF under Chapter VII of the UN Charter, was also passed and then reaffirmed in UNSC Resolutions 1386 (2001), 1510 (2003) and 1833 (2008). [16]

Tier 2: At the mid-level, there exists a MTA between the ISAF multinational entity and the Government of the Islamic Republic of Afghanistan (GIRoA), under which ‘the Government of Afghanistan has agreed to the presence of ISAF forces on its territory and their status while there’.[17]  

Tier 3: Finally, at the lower national level, there are a range of national mandates authorising the deployment of national armed forces to Afghanistan.  To illustrate using New Zealand as an example, the NZDF ISAF contingent operates under: firstly, a national mandate, issued yearly by successive New Zealand governments; and secondly, a separate SOFA between the New Zealand government and the GIRoA regarding the status of all NZDF personnel deployed to Afghanistan.[18] 

These three tiers of politico-legal mandates governing NZDF forces in Afghanistan are shown in Figure 2.1 below.

width=821Figure 2.1 – Mandates & Multinational Operations (MNOs): The mandate structure governing the NZDF deployment to the ISAF mission in Afghanistan.

Key for ROE: National Mandates

It is the national mandates, at the lower level, which are of greatest interest and concern to this research on the impact of diverse national mandates – and specifically ROE – on a united and effective ISAF campaign in Afghanistan, or indeed any multinational security operation.  Since all armed forces and assets operating within a MNO are contributed by national governments, and the conduct of each national contingent is governed and restrained in its own way by mandates issued from each of the respective governments, it is these national mandates which will most dramatically impact on the effectiveness of the MNO since they contain the potential to empower or impair each national contingent’s contribution to the multinational endeavour. 

The instructions within these mandates are the politico-legal puppet strings by which the “boots on the ground” are ultimately controlled by national governments, regardless of higher organisational authorities.  Indeed, in many ways instructions within national mandates take precedence over those issued by the Operational Command Headquarters at higher levels within the MNO’s command structure.  This is because the first responsibility of national armed forces deployed to an overseas theatre is to obey the politico-legal instructions issued from political masters within the national government at home – regardless of whether these instructions bypass the official PSO command structure or even contradict strategic and tactical plans and policies issued by multinational command in theatre.

This situation therefore raises the question, what kind of instructions exactly are contained within national mandates that render the latter so powerful for the effective prosecution of MNOs? According to LTCOL Andrew Shaw, Commanding Officer of the NZDF Command & Staff College at Trentham Military Camp, national mandates are very specific.  They authorise the deployment of a set number of people, in a particular organisational configuration, to do specified tasks towards a selected objective, for a precise period of time, operating within a defined budget, and with a list of specific operational constraints (see Figure 2.2). [19] 


Figure 2.2 – National Mandates: The various components of a national mandate.

 Of these various sets of instructions, it is the latter list of specific operational constraints within which the specified tasks must be accomplished – namely, ROE – which is of greatest interest and importance to this research.  This is because ROE are the central mechanism within the national mandate by which political masters may exercise political and operational control over security forces, and thereby guide and constrain the actions of the deployed military force, regardless of its size, strength or configuration.  

Indeed, it seems to be these ROE that ultimately determine the true effectiveness of the contingent, both in the accomplishment of its tasks and as a contributing unit within the wider mission.  

*This blog is an excerpt taken from Dr Regeena Kingsley’s original doctoral research in Defence & Strategic Studies (2014) entitled: “Fighting against Allies: An Examination of “National Caveats” within the NATO-led International Security Assistance Force (ISAF) Campaign in Afghanistan & their Impact on ISAF Operational Effectiveness, 2002-2012”. 
Dr Kingsley’s full Thesis and its accompanying volume of Appendices can be viewed and downloaded from Massey University’s official website here: http://mro.massey.ac.nz/xmlui/handle/10179/6984


[1] New Zealand Defence Force (NZDF), Directorate of Legal Services, ‘11.0 Rules of Engagement’, in NZDF Operational Law Companion, May 1999, paragraph 11.2, p. 11-1.

[2] Ibid., paragraphs 11.3-11.8, p. 11-1; ‘Georges Clemenceau Quotes’, ThinkExist.Com, http://thinkexist.com/quotation/war-is-much-too-serious-a-matter-to-entrust-to/533942.html, (accessed 9 November 2009).

[3] NZDF, ‘11.0 Rules of Engagement’, op. cit., paragraph 11.9, p. 11-1.

[4]  The Geneva Conventions include the following international legal treaties: Geneva Convention for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field (1864); Geneva Convention for the Amelioration of the Condition of the Wounded and Sick in Armies at Sea (1906); Geneva Convention relative to the Treatment of Prisoners of War (1929); Geneva Convention (I) for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field (1949); Geneva Convention (II) for the Amelioration of the Condition of the Wounded, Sick and Shipwrecked Members of Armed Forces at Sea (1949); Geneva Convention (III) Relative to the Treatment of Prisoners of War (1949); Geneva Convention (IV) Relative to the Protection of Civilian Persons in Time of War (1949); Protocol Additional to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of International Armed Conflicts (Protocol I) (1977); Protocol Additional to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of Non-International Armed Conflicts (Protocol II) (1977); Protocol Additional to the Geneva Conventions of 12 August 1949, and Relating to the Adoption of an Additional Distinctive Emblem (Protocol III) (2005).

[5] Ibid., paragraph 11.3, p. 11-1.

[6] NZDF BRIG Roger Mortlock (Ret’d), Personal communication with Regeena Kingsley, 3 November 2009, Centre for Defence & Security Studies (CDSS), Massey University, Palmerston North, New Zealand.

[7] NATO Standardization Agency (NSA), Glossary of Terms and Definitions (English and French), AAP-6(2008), 2008, p. 2-R-10, http://www.fas.org/irp/doddir/other/nato2008.pdf, (accessed 6 January 2011); NATO Partnership for Peace (PfP), ‘Rules of Engagement in Multinational Operations against Terrorism’, Generated from a PfPLMS 0.2 learning object, NATO Partnership for Peace Forum (PfP ADL-WG, 2006), p. 1, http://pfpdev.ethz.ch/SCORMcontent/112363/scos/5/index.pdf, (accessed 8 October 2009).

This definition was agreed upon by NATO and entered both NATO’s lexicon and its official ‘Glossary of Terms’ on 1 January 1973 (NATO Standardization Agency (NSA), Glossary of Terms and Definitions (English and French), AAP-6(2008), ibid., p. II, 2-R-10).

The ‘NATO Agreed’ definition is also currently adhered to and in use within the United States military (a NATO nation), but also interestingly within the Australian Defence Force (a non-NATO nation), and can be viewed within these nations official Glossary of Terms publications (for example: U.S. Department of Defense (U.S. DoD), The Dictionary of Military Terms, Joint Pub 1-02, New York, Skyhorse Publishing, 2009, p. 477; and Australian Department of Defence, ADFP 101 Glossary, Australian Defence Force Publication- Staff Duties Series, Canberra, 2009, p. R-11).

[8] NZDF AIRCDRE Greg Elliott, Official communication to Regeena Kingsley via the New Zealand Embassy in Washington D.C., [Email], 26 August 2010, Washington D.C., United States; NZDF LTCOL Justin S. Emerson, Personal correspondence with Regeena Kingsley, [Letter], 3 September 2009, Headquarters New Zealand Defence Force, Wellington.

[9] A. Heywood, Key Concepts in Politics, New York, Palgrave Macmillan, 2000, p. 208.

[10] A. Heywood, Politics, (3rd ed.), New York, Palgrave Macmillan, 2007, pp. 252, 452.

[11] UNSC resolutions require a majority vote among the fifteen sitting members of the Security Council at any one time, and no vetoes by the five permanent members (J. Goldstein & J. Pevehouse. International Relations, (4th ed.), USA: Pearson International Edition, 2008, p. 225; ‘Member States – Growth in UN Membership, 1945-present’, Official Website of the United Nations, http://www.un.org/en/members/growth.shtml, (accessed  28  October  2009).

[12]  Goldstein & Pevehouse. ibid., p. 227.

[13] Heywood, Key Concepts in Politics, 2000, op. cit., p. 29; Heywood, Politics (3rd ed.) 2007, op. cit., p. 219.

[14] A Status of Armed Forces Agreement (SOFA) refers to a binding political treaty drawn up to define the legal ‘status’ of armed forces operating in the territory of another State.  It reaffirms the historic ‘Law of the Flag’ principle, whereby armed soldiers of a friendly State in the territory of another State were subject to the laws of their own national flag, rather than the laws of the foreign lands through which they passed.  Though this is a widely recognised principle under international law, it is now customary for States to enter into SOFAs with the host State (or ‘forum State’) before deploying or stationing troops to that territory to ‘govern the relationship between military forces of a state and the civilian authorities of a foreign state in which they are located or through which they are passing’.

The content of SOFAs can vary markedly depending on the circumstances surrounding the deployment and the activity to be engaged in.  For instance, there are four different types of SOFA: (1) peacetime or ‘training’ SOFA; (2) UN or peacekeeping SOFA; (3) operational SOFA; and (4) Special Purpose SOFA.  The principal purpose of a SOFA does not vary, however, in that it delineates the respective rights and obligations of both Parties to the treaty in terms of legal jurisdiction. 

Usually this means that the host State will restrict or waive its inherent right ‘to exercise jurisdiction over all persons found within its borders regardless of whether they are in the service of a foreign armed force or not’.  The incoming State is granted ‘sovereign immunity’, meaning that it ‘is not subject to the jurisdiction of a foreign court in respect of acts which it or its instrumentalities do in the forum state in the exercise of its sovereignty as a state (e.g. military and diplomatic activities)’. The incoming State will for its part, while acknowledging respect for the local law and customs, agree to impose upon itself certain obligations: (1) to exercise criminal and disciplinary jurisdiction over its armed forces; (2) to regulate this criminal jurisdiction in respect of specified classes of offenses; (3) to make modifications or exemptions to domestic law relating to the force (such as taxation, customs, vehicle licensing) as necessary; and (4) to establish a claims regime for the resolution of civilian claims against the force for damaged property.  

SOFAs may additionally cover a wide range of issues and even devise solutions for theoretical scenarios, such as the resolution of potential disputes between the States (New Zealand Defence Force (NZDF), Directorate of Legal Services, ‘14.0 The Legal Status of Armed Forces in the Territory of a Foreign State’, in NZDF Operational Law Companion , May 1999, paragraphs 14.0. 14.2, 14.5, 14.11, 14.12, 14.21, 14.23, 14.32, 14.33. 14.43, 14.46, pp. 14-i-14-ii, 14-1-14-6).

*For written NZDF authorisation permitting the use of these sections within the NZDF Operational Law Companion, refer to p.  xxiii-xxxiv of Volume I: Thesis in my doctoral research, accessible here: http://mro.massey.ac.nz/handle/10179/6984.

[15] NZDF LTCOL Justin S. Emerson, Personal correspondence with Regeena Kingsley, op. cit.

[16] Ibid.

[17] Ibid.

[18] Ibid.

[19] NZDF LTCOL Andrew Shaw, Interviewed by Regeena Kingsley, 23 November 2009, NZDF Command & Staff College, Trentham Military Camp, Wellington, New Zealand.