Source: https://ihl-databases.icrc.org/customary-ihl/eng/docs/v2_rul_rule57
Timestamp: 2019-04-24 09:05:23+00:00

Document:
Regulations concerning the Laws and Customs of War on Land, annexed to Convention (II) with Respect to the Laws and Customs of War on Land, The Hague, 29 July 1899, Article 24.
Regulations concerning the Laws and Customs of War on Land, annexed to Convention (IV) respecting the Laws and Customs of War on Land, The Hague, 18 October 1907, Article 24.
Protocol Additional to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts (Protocol I), Geneva, 8 June 1977, Article 37(2). Article 37 was adopted by consensus. CDDH, Official Records, Vol. VI, CDDH/SR.39, 25 May 1977, p. 103.
Ruses of war, that is to say, those acts which, without inviting the confidence of the adversary, are intended to mislead him or to induce him to act recklessly, such as camouflage, traps, mock operations and misinformation, are not perfidious acts.
This Article 21 was amended and adopted in Committee III of the CDDH by 21 votes in favour, 15 against and 41 abstentions.
The approved text provided: “Ruses are not prohibited”.
Military necessity … allows … of such deception as does not involve the breaking of good faith either positively pledged, regarding agreements entered into during the war, or supposed by the modern law of war to exist.
Furthermore, Article 101 of the Lieber Code describes deception as a “just and necessary means of hostility”.
Project of an International Declaration concerning the Laws and Customs of War, Brussels, 27 August 1874, Article 14.
Australia, Law of Armed Conflict, Commanders’ Guide, Australian Defence Force Publication, Operations Series, ADFP 37 Supplement 1 – Interim Edition, 7 March 1994, § 508.
Australia, Law of Armed Conflict, Commanders’ Guide, Australian Defence Force Publication, Operations Series, ADFP 37 Supplement 1 – Interim Edition, 7 March 1994, § 901 (land warfare); see also § 826 (naval warfare).
Ruses of war and the employment of measures necessary for obtaining information about the enemy and the enemy country are permissible. Ruses of war are used to obtain an advantage by misleading the enemy. They are permissible provided they are free from any suspicion of treachery or perfidy. Legitimate ruses include surprises, ambushes, camouflage, decoys, mock operations and misinformation. Psychological operations are also permitted.
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 702.
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, § 7.2.
In order to conceal his intentions and actions from the enemy to induce him to react in a way detrimental to his interests, a military commander is permitted to use ruse … A ruse of war aims to: mislead the enemy [and] to induce the enemy to act recklessly.
Burundi, Règlement n° 98 sur le droit international humanitaire, Ministère de la Défense Nationale et des Anciens Combattants, Projet “Moralisation” (BDI/B-05), August 2007, Part I bis, p. 16; see also Part I bis, pp. 32, 41 and 94.
In order to be compatible with the law of war, camouflage must respect the difference between ruses (permitted) and perfidy (prohibited).
Cameroon’s Instructor’s Manual (1992) provides that ruses of war and stratagems are different from perfidy. They are lawful deceptions.
Deception includes “ruses of war” and “stratagems” and is different from perfidy. A ruse of war is an act whose aim it is to mislead the enemy, or to make him behave imprudently. In the case of a ruse of war, one may use camouflage, decoys or feints, misinformation, simulated operations, electronic disturbances, etc.
Cameroon, Droit des conflits armés et droit international humanitaire, Manuel de l’instructeur en vigueur dans les forces de défense, Ministère de la Défense, Présidence de la République, Etat-major des Armées, 2006, p. 222, § 222; see also p. 103, § 371 and p. 147, § 431.
Commanders are authorized to use military deception to protect against attack and to enhance the security and effectiveness of Canadian forces. Commanders may employ any deception means available to deny potentially hostile forces the ability to accurately locate, identify, track, and target Canadian or Coalition forces except as constrained or otherwise prohibited by international law or agreement, directive or these ROE.
Canada, Canadian Joint Force Somalia: Rules of Engagement Operation Deliverance, completed on 11 December 1992, reprinted in James M. Simpson, Law Applicable to Canadian Forces in Somalia 1992/93. A study prepared for the Commission of Inquiry into the Deployment of Canadian Forces to Somalia, Minister of Public Works and Government Services, Ottawa, 1997, Appendix, pp. 73–80, § 27.
Ruses of war are measures taken to obtain advantage of the enemy by confusing or misleading them.
Ruses of war are more formally defined as acts which are intended to mislead an adversary or to induce that adversary to act recklessly. Ruses must not infringe any rule of the LOAC. Ruses are lawful if they are not treacherous, perfidious and do not violate any express or tacit agreement.
q. giving false ground signals to enable airborne personnel or supplies to be dropped in a hostile area or to induce aircraft to land in a hostile area.
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, pp. 6-1 and 6-2, §§ 5–7 (land warfare); see also p. 7-2, §§ 14 and 15 (air warfare) and p. 8-10, §§ 75–77 (naval warfare).
In the context of air warfare, the manual also gives camouflage, decoys and fake radio signals as examples of legitimate ruses.
Canada, The Law of Armed Conflict at the Operational and Tactical Level, Office of the Judge Advocate General, 1999, p. 7-2, § 15.
1. Ruses of war are measures taken to obtain advantage of the enemy by confusing or misleading them.
2. Ruses of war are more formally defined as acts, which are intended to mislead an adversary or to induce that adversary to act recklessly. Ruses must not infringe any rule of the LOAC. Ruses are lawful if they are not treacherous, perfidious and do not violate any express or tacit agreement.
q. giving false ground signals to enable airborne personnel or supplies to be dropped in a hostile area, or to induce aircraft to land in a hostile area.
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 602.
2. Ruses of war are more formally defined as acts that are intended to mislead an adversary or to induce that adversary to act recklessly. Ruses must not infringe any rule of the LOAC. Ruses are lawful if they are not treacherous, perfidious and do not violate any express or tacit agreement. Examples of legitimate ruses include camouflage, decoys and fake radio signals.
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 705.
g. pretending to communicate with forces that do not exist.
Canada, The Law of Armed Conflict at the Operational and Tactical Levels, Office of the Judge Advocate General, 13 August 2001, § 856.1–3.
False and improper use of the Red Cross/Red Crescent emblem is prohibited. The use of the Red Cross to shield the movement of troops or ammunitions is also prohibited. Perfidy is a war crime. Committing a hostile act under the cover of the protection provided by the distinctive emblem would constitute perfidy. Ruses such as camouflage and other similar deceptions are not prohibited and as such are legitimate.
Chad’s Instructor’s Manual (2006) states that “ruses of war” are permitted.
- mock operations, decoys, pretence.
- What are the means and methods of warfare that can be used?
A ruse of war is intended to mislead the adversary and to induce him to act recklessly. It must not infringe the rules of the law of war.
Examples of ruses of war are: decoys, camouflage, misinformation, mock operations.
- false information, disinformation or psychological operations intended to sow confusion or to demoralize, under the condition that the intention is not to spread terror among the civilian population.
All measures of deception of that type are perfectly lawful under the law. On the other hand, IHL prohibits recourse to perfidy with the aim to kill, injure or capture an enemy.
Ruses of war are more officially defined as acts intended to mislead an adversary or to induce him to act recklessly. They must not infringe any rule whatsoever of IHL. They are lawful if they are not treacherous or perfidious acts and if they do not violate any tacit or express understanding whatsoever.
Côte d’Ivoire, Droit de la guerre, Manuel d’instruction, Livre IV: Instruction du chef de section et du commandant de compagnie, Manuel de l’élève, Ministère de la Défense, Forces Armées Nationales, November 2007, p. 45.
The law of armed conflicts permits deceiving the enemy through stratagems and ruses of war intended to mislead him, to deter him from taking action, or to induce him to act recklessly, provided the ruses do not violate rules of international law applicable to armed conflict.
Stratagems and ruses of war permitted in armed conflict include such deceptions as camouflage, deceptive lighting, dummy ships and other armament, decoys, simulated forces, feigned attacks and withdrawals, ambushes, false intelligence information, electronic deceptions, and utilization of enemy codes, passwords, and countersigns.
Ecuador, Aspectos Importantes del Derecho Internacional Marítimo que Deben Tener Presente los Comandantes de los Buques, Academia de Guerra Naval, 1989, §§ 12.1 and 12.1.1.
France’s LOAC Manual (2001) incorporates the content of Article 24 of the 1907 Hague Regulations.
France, Manuel de droit des conflits armés, Ministère de la Défense, Direction des Affaires Juridiques, Sous-Direction du droit international humanitaire et du droit européen, Bureau du droit des conflits armés, 2001, p. 114.
The manual defines “lawful deception: the ruse of war or stratagem is a non-perfidious act but aimed at deceiving the enemy or inducing him to act recklessly”.
France, Manuel de droit des conflits armés, Ministère de la Défense, Direction des Affaires Juridiques, Sous-Direction du droit international humanitaire et du droit européen, Bureau du droit des conflits armés, 2001, p. 47; see also p. 114.
The manual gives the examples of camouflage, decoy, feint, simulated demonstration or operation, disinformation, false information and technical ruses.
France, Manuel de droit des conflits armés, Ministère de la Défense, Direction des Affaires Juridiques, Sous-Direction du droit international humanitaire et du droit européen, Bureau du droit des conflits armés, 2001, pp. 47 and 114; see also p. 115.
The manual also incorporates the content of Article 37(2) of the 1977 Additional Protocol I.
Ruses of war and the employment of measures necessary for obtaining information about the adverse party and the country are considered permissible … Ruses of war include e.g. the use of enemy signals, passwords, signs, decoys, etc.; not, however, espionage.
Germany, Humanitarian Law in Armed Conflicts – Manual, DSK VV207320067, edited by The Federal Ministry of Defence of the Federal Republic of Germany, VR II 3, August 1992, English translation of ZDv 15/2, Humanitäres Völkerrecht in bewaffneten Konflikten – Handbuch, August 1992, § 471; see also § 1018 (naval warfare).
[S]ome ruses of war in the course of hostilities which serve the purpose of disorienting the adversary without inducing him, do not constitute perfidy and therefore are permissible. Camouflage, decoys, mock operations and disinformation may serve as paradigms of permissible acts.
Greece, International Law Manual, Hellenic Navy General Staff, Directorate A2, Division IV, 1995, Chapter 5, § 5.
Hungary’s Military Manual (1992) lists camouflage, decoys, mock operations and misinformation as examples of deception.
Surprise, stratagem, artifice are some of the most fundamental principles of war, giving the army a tactical advantage, and sometimes even a strategic one. The prohibition in the chapter on methods of warfare does not come to deny the armies the use of the element of surprise or to demand that each side be “transparent” to its enemy.
One may deceive the enemy with regard to the size of one’s force or its intentions, as was done in the Yom Kippur War by the “Zvika Force”. It is also allowed to conduct maneuvers of deception, flanking, dummy units and weapons, and the like. The law of war does not come to bar any party from exploiting tactical or strategic advantages or the enemy’s naivete.
Israel, Laws of War in the Battlefield, Manual, Military Advocate General Headquarters, Military School, 1998, pp. 56 and 58.
Combatants must wear a permanent sign of recognition which can be recognised from afar … Naturally, this does not mean wearing identification that is likely to endanger the wearer (such as a hat that is luminous in the dark) nor does it prevent the use of camouflage that makes use of the conditions in the field (hiding among trees and bushes).
Israel, Rules of Warfare on the Battlefield, Military Advocate-General’s Corps Command, IDF School of Military Law, Second Edition, 2006, p. 31.
Surprise, deception and dishonesty are among the most basic principles of war, gaining a tactical and even a strategic advantage for the army. The ban in the annals of the rules of engagement is not designed to prevent armies from using surprise tactics and does not require each side to be “transparent” in the face of its enemy. The distinction between trickery (which is permitted) and betrayals of trust or treachery is that the latter are defined as acts designed to cause the enemy to think that it is entitled to the protection of the rules of war or to create a situation in which it is obliged to put its trust in the opposing side through the intention to betray such trust.
There is no ban on using deception, trickery, ambushes and misleading tactics that are not treachery. Take, for example, a fighter concealing himself in features of the natural (as opposed to the human) surroundings (It is permitted to blacken the face, add leaves to the helmet, etc.). It is permitted to disrupt the enemy’s network of communications and psychological warfare is also permitted. During the Gulf War, the Coalition planes dropped “safe conduct passes” over the Iraqi army soldiers, promising immunity to any soldier showing the slip of paper and laying down his arms. It is permitted to mislead the enemy with respect to the size of your force or its intentions as was done during the Yom Kippur War by the “Zvika Force” and it is also possible to use false manoeuvres, outflanking movements and decoys. The rules of war are not designed to prevent the use of tactical or strategic advantages or the naivety of the enemy, but to lay down basic rules of the game so that anyone who is entitled to be protected is not frightened to lay down their weapons.
Italy, Manuale di diritto umanitario, Introduzione e Volume I, Usi e convenzioni di Guerra, SMD-G-014, Stato Maggiore della Difesa, I Reparto, Ufficio Addestramento e Regolamenti, Rome, 1991, Vol. I, § 9.
A commander in his desire to fulfil his mission shall not mask his intentions and action from the enemy so as to induce the enemy to react in a manner prejudicial to his interests. Thus, to be consistent with the law of war, deceptions shall follow the distinction between permitted ruses and prohibited perjury [perfidy] … [Ruse] of war is considered to be a permissible method of warfare. These are acts intended to mislead an adversary or induce him to act recklessly but they infringe no rule of international law and are not perfidious because they do not invite the confidence of an adversary with respect to protection under that law. Examples of ruses of war are camouflage, decoys, mock operations, misinformation, surprises, ambushes and small scale raids.
Nigeria, International Humanitarian Law (IHL), Directorate of Legal Services, Nigerian Army, 1994, pp. 42 and 43.
Nigeria’s Manual on the Laws of War states: “Stratagems and ruses of war are measures to obtain advantage over the enemy by misleading or mystifying him. Such tactics are permissible provided they do not involve treachery.” It gives examples of “legitimate tactics”, such as surprises, ambushes, feigning attacks, retreats, flights and false movement of units, making use of the enemy code and password, giving false information to the enemy, employing spies and agents, moving landmarks, using dummies and psychological warfare.
(1) In order to fulfil their mission, commanders [may] attempt to mislead the enemy about their intentions and actions or conceal them to induce him to act recklessly. For this to be compatible with the law of armed conflict, a distinction must be made between ruses of war (permitted) and perfidy (prohibited).
(b) induce the enemy to act recklessly.
(e) technological ruses (electronics, communications).
Peru, Manual de Derecho Internacional Humanitario para las Fuerzas Armadas, Resolución Ministerial Nº 1394-2004-DE/CCFFAA/CDIH-FFAA, Lima, 1 December 2004, § 27.e.(1)–(3).
Peru, Manual de Derecho Internacional Humanitario para las Fuerzas Armadas, Resolución Ministerial Nº 1394-2004-DE/CCFFAA/CDIH-FFAA, Lima, 1 December 2004, § 135.b.
Stratagems are legal at all times.
Deceiving the enemy by camouflaging air bases, simulating traces, misleading by electronic means or even using the enemy’s SIF (Selective Identification Feature) or IFF (Identification Friend or Foe) to penetrate its air defence system are perfectly legal aerial tactics or methods.
Peru, Manual de Derecho Internacional Humanitario para las Fuerzas Armadas, Resolución Ministerial Nº 1394-2004-DE/CCFFAA/CDIH-FFAA, Lima, 1 December 2004, § 165.a.
Ruses of war … [a]re acts whose objective is to mislead the enemy and to induce him to act recklessly but which do not violate any norm of international law and which are not perfidious because they do not appeal to the adversary’s good faith regarding the protection afforded by international law.
(1) In order to fulfil their mission, commanders [may] attempt to mislead the enemy about their intentions and actions or conceal them to induce him to act recklessly. For this to be compatible with international humanitarian law, a distinction must be made between ruses of war (permitted) and perfidy (prohibited).
Peru, Manual de Derecho Internacional Humanitario y Derechos Humanos para las Fuerzas Armadas, Resolución Ministerial No. 049-2010/DE/VPD, Lima, 21 May 2010, § 28(e), p. 238; see also § 46, p. 423.
Peru, Manual de Derecho Internacional Humanitario y Derechos Humanos para las Fuerzas Armadas, Resolución Ministerial No. 049-2010/DE/VPD, Lima, 21 May 2010, § 126(b), p. 238.
Peru, Manual de Derecho Internacional Humanitario y Derechos Humanos para las Fuerzas Armadas, Resolución Ministerial No. 049-2010/DE/VPD, Lima, 21 May 2010, § 166(a), p. 339.
The Republic of Korea’s Military Law Manual (1996) states that ruses of war such as camouflage, decoys and misinformation are permitted. It adds that the dissemination of misinformation during some landing operations is also lawful.
Ruses of war are not prohibited. Such ruses are acts which are intended to mislead an adversary as to the military unit’s condition, position and nature of operations. The following are examples of such ruses: demonstrations, misinformation, simulation and other actions stipulated by combat manuals in order to deceive the enemy and not violating the rules of international humanitarian law.
Spain, El Reglamento para el Servicio de Campaña, 4 January 1882, § 863.
Spain’s LOAC Manual (1996) states that stratagems are permitted.
Spain, Orientaciones. El Derecho de los Conflictos Armados, Publicación OR7-004, 2 Tomos, aprobado por el Estado Mayor del Ejército, Division de Operaciones, 18 March 1996, Vol. I, §§ 3.3.a.(1), 5.3.c, 7.3.a.(6) and 10.8.e.(1).
The manual adds that, in order to fulfil his mission, the commander may dissimulate his intentions and actions to the enemy in order to mislead him, to induce him to act recklessly or to react against his own interests. However, stratagems must neither infringe any rule of international law applicable in armed conflicts, nor be perfidious.
Spain, Orientaciones. El Derecho de los Conflictos Armados, Publicación OR7-004, 2 Tomos, aprobado por el Estado Mayor del Ejército, Division de Operaciones, 18 March 1996, Vol. I, §§ 3.3.a.(1) and 5.3.c; see also §§ 2.3.b.(2) and 7.3.a.(6).
The manual gives the following examples of stratagems: decoys, mock operations, misinformation, camouflage and disinformation.
In order to fulfil their mission, commanders attempt to conceal their intentions and actions, using stratagems and ruses of war. Ruses of war are a legitimate method of warfare, combining deception and trickery to mislead an adversary or induce him to act recklessly or take the wrong decision. However, some ruses of war are prohibited, when they involve perfidy, that is, if they appeal to the good faith of the adversary with the intention of betraying him, misleading him into thinking that certain persons or objects cannot be attacked because they are protected by the law of armed conflict; e.g. the use of an ambulance to transport munitions.
Spain, Orientaciones. El Derecho de los Conflictos Armados, Tomo 1, Publicación OR7–004, (Edición Segunda), Mando de Adiestramiento y Doctrina, Dirección de Doctrina, Orgánica y Materiales, 2 November 2007, § 2.3.b.(3); see also §§ 3.3.a.(1), 5.3.c and 7.3.a.6.
The manual gives the following examples of ruses of war: “decoys, mock operations, camouflage and misinformation”.
Spain, Orientaciones. El Derecho de los Conflictos Armados, Tomo 1, Publicación OR7–004, (Edición Segunda), Mando de Adiestramiento y Doctrina, Dirección de Doctrina, Orgánica y Materiales, 2 November 2007, § 3.3.a.(1); see also § 7.3.a.(6).
In certain circumstances, ruses of war may become almost tantamount to perfidy. Here the important difference is that ruses of war are not based on betrayal of the adversary’s confidence. Instead, the intention of a ruse is to mislead the adversary, which can lead to incorrect deployment of his forces or to reckless actions which, for example, prematurely reveal his forces, intended tactics or assault objectives. The [1907 Hague Regulations] states that it is permitted to use ruses of war, and the same authority is given in [the 1977 Additional Protocol I], Article 37:2. Typical examples of ruses are giving false information on the size of one’s own forces, position and intentions, or hiding one’s combat forces with camouflage, or misleading the adversary by means of mock objectives and mock operations.
Sweden, International Humanitarian Law in Armed Conflict, with reference to the Swedish Total Defence System, Swedish Ministry of Defence, January 1991, Section 3.2.1.1.b, p. 30.
Ruses of war and the employment of methods necessary for obtaining information about the enemy and the country are lawful.
Examples of lawful ruses: surprises; ambushes; feigning attacks or retreats; constructing installations which it is not intended to use; constructing dummy airfields; putting up dummy guns or dummy tanks; giving large strong points to a small force; transmitting false information through newspapers or radio; making use of the enemy’s watchwords, wireless code signs and tuning calls to transmit false instructions; pretending to communicate with troops or reinforcements which do not exist; moving landmarks; removing from uniforms the badges indicating the grade, unit, nationality or speciality; giving the men of a single unit badges of several different units so that the enemy thinks that he is facing a bigger force; inciting enemy soldiers to rebellion, mutiny or desertion, possibly taking with them arms and means of transportation such as aircraft; and inducing the enemy population to revolt against its government, etc.
Switzerland, Lois et coutumes de la guerre (Extrait et commentaire), Règlement 51.7/II f, Armée Suisse, 1987, Article 38, including commentary.
Switzerland, Bases légales du comportement à l’engagement (BCE), Règlement 51.007/IVf, Swiss Army, issued based on Article 10 of the Ordinance on the Organization of the Federal Department for Defence, Civil Protection and Sports of 7 March 2003, entry into force on 1 July 2005, § 219.
1.2.44. … Ruses of war are not prohibited by international humanitarian law … Such ruses are acts which are intended to mislead an adversary (e.g. the use of camouflage, mock operations, misinformation, decoys).
2.1.11. During preparation and conduct of hostilities one should clearly distinguish between perfidy … and ruses of war.
Ukraine, Manual on the Application of IHL Rules, Ministry of Defence, 11 September 2004, §§ 1.2.44 and 2.1.11.
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 307.
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 307, footnote 1.
Surprises; ambushes; feigning attacks, retreats or flights; simulating quiet and inactivity; giving large strong points to a small force; constructing works, bridges, etc., which it is not intended to use; transmitting bogus signal messages, and sending bogus despatches and newspapers with a view to their being intercepted by the enemy; making use of the enemy’s signals, watchwords, wireless code signs and tuning calls, and words of command; conducting a false military exercise on the wireless on a frequency easily interrupted while substantial troop movements are taking place on the ground; pretending to communicate with troops or reinforcements which do not exist; moving landmarks; constructing dummy airfields and aircraft; putting up dummy guns or dummy tanks; laying dummy mines; removing badges from uniforms; clothing the men of a single unit in the uniform of several different units so that prisoners and dead may give the idea of a large force; giving false ground signals to enable airborne personnel or supplies to be dropped in a hostile area, or to induce aircraft to land in a hostile area.
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 312.
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 484.
According to the manual, ruses of war include the use of camouflage, decoys, mock operations, dummy installations, misleading messages and misinformation.
United Kingdom, The Law of Armed Conflict, D/DAT/13/35/66, Army Code 71130 (Revised 1981), Ministry of Defence, prepared under the Direction of The Chief of the General Staff, 1981, Section 4, p. 12, § 2(a) and Annex A, p. 46, § 4.
Ruses of war are not prohibited. Such ruses are acts which are intended to mislead an adversary or to induce him to act recklessly but which infringe no rule of international law applicable in armed conflict and which are not perfidious because they do not invite the confidence of the adversary with respect to protection under the law.
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 5.17.
Ruses of war are permitted. Warships and auxiliary vessels, however, are prohibited from launching an attack whilst flying a false flag, and at all times from actively simulating the status of those vessels exempt from attack.
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 13.82.
Absolute good faith with the enemy must be observed as a rule of conduct; but this does not prevent measures such as using spies and secret agents, encouraging defection or insurrection among the enemy civilian population, corrupting enemy civilians or soldiers by bribes, or inducing the enemy’s soldiers to desert, surrender, or rebel. In general, a belligerent may resort to those measures for mystifying or misleading the enemy against which the enemy ought to take measures to protect himself.
The line of demarcation between legitimate ruses and forbidden acts of perfidy is sometimes indistinct … [I]t is a perfectly proper ruse to summon a force to surrender on the ground that it is surrounded and thereby induce such surrender with a small force.
Among legitimate ruses may be counted surprises; ambushes; feigning attacks, retreats or flights; simulating quiet and inactivity; use of small forces to simulate large units; transmitting false or misleading radio or telephone messages; deception of the enemy by bogus orders purporting to have been issued by the enemy commanders; making use of the enemy’s signals and passwords; pretending to communicate with troops or reinforcements which have no existence; deceptive supply movements; deliberate planting of false information; use of spies and secret agents; moving landmarks; putting up dummy guns and vehicles or laying dummy mines; erection of dummy installations and airfields; removing unit identifications from uniforms; use of signal deceptive measures; and psychological warfare activities.
United States, Field Manual 27-10, The Law of Land Warfare, US Department of the Army, 18 July 1956, as modified by Change No. 1, 15 July 1976, §§ 48–51.
Ruses of war which have customarily been accepted as lawful, such as the use of camouflage, traps, mock operations and misinformation, are not perfidy. Ruses of war involve misinformation, deceit or other steps to mislead the enemy under circumstances where there is no obligation to speak the truth.
Article 24 of the 1907 Hague Regulations confirms the general rule that ruses of war not constituting perfidy are lawful. Among the permissible ruses are surprises, ambushes, feigning attacks, retreats, or flights; simulation of quiet and inactivity; use of small forces to simulate large units; transmission of false or misleading radio or telephone messages (not involving protection under international law such as internationally recognized signals of distress); deception by bogus orders purported to have been issued by the enemy commander; use of the enemy’s signals and passwords; feigned communication with troops or reinforcements which have no existence; and resort to deceptive supply movements. Also included are the deliberate planting of false information, moving of landmarks, putting up dummy guns and vehicles, laying of dummy mines, erection of dummy installations and airfields, removal of unit identifications from uniforms, and use of signal deceptive measures.
(1) The use of aircraft decoys. Slower or older aircraft may be used as decoys to lure hostile aircraft into combat with faster and newer aircraft held in reserve. The use of aircraft decoys to attract ground fire in order to identify ground targets for attack by more sophisticated aircraft is also permissible.
(2) Staging air combats. Another lawful ruse is the staging of air combat between two properly marked friendly aircraft with the object of inducing an enemy aircraft into entering the combat in aid of a supposed comrade.
(3) Imitation of enemy signals. No objection can be made to the use by friendly forces of the signals or codes of an adversary. The signals or codes used by enemy aircraft or by enemy ground installations in contact with their aircraft may properly be employed by friendly forces to deceive or mislead an adversary. However, misuse of distress signals or distinctive signals internationally recognized as reserved for the exclusive use of medical aircraft would be perfidious.
(4) Use of flares and fires. The lighting of large fires away from the true target area for the purpose of misleading enemy aircraft into believing that the large fires represent damage from prior attacks and thus leading them to the wrong target is a lawful ruse. The target marking flares of the enemy may also be used to mark false targets. However, it is an unlawful ruse to fire false target flare indicators over residential areas of a city or town which are not otherwise valid military objectives.
(5) Camouflage use. The use of camouflage is a lawful ruse for misleading and deceiving enemy combatants. The camouflage of a flying aircraft must not conceal national markings of the aircraft, and the camouflage must not take the form of the national markings of the enemy or that of objects protected under international law.
(6) Operational ruses. The ruse of the “switched raid” is a proper method of aerial warfare in which aircraft set a course, ostensibly for a particular target, and then, at a given moment, alter course in order to strike another military objective instead. This method was utilized successfully in World War II to deceive enemy fighter intercepter aircraft.
United States, Air Force Pamphlet 110-31, International Law – The Conduct of Armed Conflict and Air Operations, US Department of the Air Force, 1976, §§ 8–3(b), 8-4(a) and (b).
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-2.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Transportation, US Coast Guard, October 1995 (formerly NWP 9 (Rev. A)/FMFM 1-10, October 1989), §§ 12.1 and 12.1.1.
The law of armed conflict permits deceiving the enemy through stratagems and ruses of war intended to mislead him, to deter him from taking action, or to induce him to act recklessly, provided the ruses do not violate rules of international law applicable to armed conflict.
Stratagems and ruses of war permitted in armed conflict include such deceptions as camouflage; deceptive lighting; dummy ships and other armament; decoys; simulated forces; feigned attacks and withdrawals; ambushes; false intelligence information; electronic deceptions; and utilization of enemy codes, passwords, and countersigns.
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-12.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Homeland Security, US Coast Guard, July 2007, §§ 12.1 and 12.1.1.
United States, Manual for Military Commissions, published in implementation of Chapter 47A of Title 10, United States Code, as amended by the Military Commissions Act of 2009, 10 U.S.C, §§ 948a, et seq., 27 April 2010, § 5(17)(c)(1), p. IV-14.
The Socialist Federal Republic of Yugoslavia’s Military Manual (1988) states that ruses of war are lawful methods of conducting warfare which are used to deceive the enemy and achieve some advantage in battle or in the conduct of the war in general. It gives the following non-exhaustive list of ruses: all types of misinformation; simulation of large attacks, retreats, flights or panic, and any other type of simulation except vicious and perfidious ones; falsification of enemy commands; deceiving the enemy about the strength of one’s own forces and reserves; putting up dummy forts, positions, aircraft, take-off strips and minefields; use of make-believe signals, enemy watchwords, code signs and passwords; use of enemy uniforms without badges, removal of badges of ranks, units or services from one’s own uniform; and anything else that could deceive the enemy in order to achieve some advantage or which could in any other way have a psychological impact on the enemy.
Yugoslavia, Socialist Federal Republic of, Propisi o Primeri Pravila Medjunarodnog Ratnog Prava u Oruzanim Snagama SFRJ, PrU-2, Savezni Sekretarijat za Narodnu Odbranu (Pravna Uprava), 1988, § 108.
Italy, Law of War Decree, 1938, as amended in 1992, Article 36.
According to a ruling of Colombia’s Constitutional Court in 1997, the use of military tactics and stratagems must be in conformity with constitutional standards. However, it had in mind the protection of civilians rather than stratagems as a method of warfare.
Colombia, Constitutional Court, Constitutional Case No. T-303, Judgment, 20 June 1997.
The Report on the Practice of Algeria recalls the old Islamic principle whereby “la guerre est ruse” (war is ruse). The report notes that Algerian fighters during the war of independence predominantly used methods of war such as surprise attacks, ambushes, camouflage, misinformation and mock operations.
Report on the Practice of Algeria, 1997, Chapter 2.4.
On the basis of the reply by Iraq’s Ministry of Defence to a questionnaire, the Report on the Practice of Iraq states that ruses of war are permitted as long as they do not contravene religious and moral rules or local and international traditions.
According to the Report on the Practice of Malaysia, members of security forces who were interviewed indicated that, in practice, deception such as camouflage would be used in conducting operations.
Report on the Practice of Malaysia, 1997, Chapter 2.4.
As an example of a ruse of war, a commentator recalled that, during the War in the South Atlantic, the United Kingdom announced the establishment of a “maritime exclusion zone”. The impression was given that a UK nuclear submarine was on station in the area. There were later complaints that misleading information had been released, when it was discovered that the vessel was in Scotland. Since the exclusion zone was not a formal blockade (it only applied to enemy naval vessels), which must be enforceable to be binding, it could be considered as a mere warning to Argentine naval forces. The commentator stated that “this was a perfectly valid and successful piece of ‘disinformation’”.
Howard S. Levie, “The Falklands Crisis and the Laws of War”, in Alberto R. Coll and Anthony C. Arend (eds.), The Falklands War: Lessons for Strategy, Diplomacy and International Law, George Allen & Unwin, Boston, 1985, p. 65.
A training video on IHL produced by the UK Ministry of Defence states that ruses are permitted but underlines that it is difficult to differentiate ruses of war and treachery.
There were few examples of perfidious practices during the Persian Gulf War. The most publicized were those associated with the battle of Ras Al-Khafji, which began on 29 January. As that battle began, Iraqi tanks entered Ras Al-Khafji with their turrets reversed, turning their guns forward only at the moment action began between Iraqi and Coalition forces. While there was some media speculation that this was an act of perfidy, it was not; a reversed turret is not a recognized indication of surrender per se. Some tactical confusion may have occurred, since Coalition ground forces were operating under a defensive posture at that time, and were to engage Iraqi forces only upon clear indication of hostile intent, or some hostile act.
United States, Department of Defense, Final Report to Congress on the Conduct of the Persian Gulf War, 10 April 1992, Appendix O, The Role of the Law of War, ILM, Vol. 31, 1992, pp. 631–632.
Howard S. Levie, The Code of International Armed Conflict, Oceana Publications, London, 1985, Vol. 1, Chapter 3.5, Section 35.1, p. 118.
To be consistent with the law of war, deception shall follow the distinction between permitted ruses and prohibited perfidy.
b) to induce the enemy to act recklessly.
Ruses of war are permitted.
Frédéric de Mulinen, Handbook on the Law of War for Armed Forces, ICRC, Geneva, 1987, §§ 400–402.
the use of spies and secret agents, encouraging defection or insurrection among enemy civilians, corrupting enemy civilians or soldiers by bribes, or encouraging the enemy’s combatants to desert, surrender or rebel (but not selectively to assassinate a particular individual), … surprise attacks, ambushes, simulating quiet and inactivity, use of small units to simulate large forces, transmitting false or misleading messages, making use of the enemy’s signals, pretending to communicate with troops or reinforcements which do not exist, moving landmarks and route markers, putting up dummy weapons and the laying of dummy mines.
Michael Bothe, Karl Joseph Partsch, Waldemar A. Solf (eds.), New Rules for Victims of Armed Conflicts, Martinus Nijhoff, The Hague, 1982, pp. 202 and 207.
Camouflaging one’s own defence positions and using them for ambushes, setting up surprise attacks from such camouflaged positions, simulating operations of retreat, as well as simulating operations of attack, using dummy weapons, transmitting misleading messages, inter alia, by using the adversary’s radio wavelengths, passwords, and codes, infiltrating the enemy’s command chain in order to channel wrong orders, moving landmarks and route markers, giving members of one military unit the signs of other units to persuade the enemy that one’s force is larger than it really is – all these are established elements of traditional tactics.
Stefan Oeter, Methods and Means of Combat, in Dieter Fleck (ed.), The Handbook of Humanitarian Law in Armed Conflicts, Oxford University Press, Oxford, 1995, pp. 199–200, § 471.

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