Source: https://ihl-databases.icrc.org/customary-ihl/eng/docs/v1_rul_rule57
Timestamp: 2019-04-25 00:16:34+00:00

Document:
Rule 57. Ruses of war are not prohibited as long as they do not infringe a rule of international humanitarian law.
This is a long-standing rule of customary international law already recognized in the Lieber Code and the Brussels Declaration, and codified in the Hague Regulations. It is also set forth in Additional Protocol I.
The rule permitting ruses of war is stated in numerous military manuals. It is supported by several official statements and other practice.
This rule was included in the draft of Additional Protocol II by Committee III of the Diplomatic Conference leading to the adoption of the Additional Protocols, but was deleted at the last moment as part of a package aimed at the adoption of a simplified text. In addition, it is contained in other instruments pertaining also to non-international armed conflicts.
The rule permitting ruses of war provided they do not infringe a rule of international humanitarian law is set forth in military manuals which are applicable in or have been applied in non-international armed conflicts. Colombia’s Constitutional Court ruled in 1997 that the use of military tactics and stratagems must be in conformity with constitutional standards, implicitly recognizing that they may be applied in non-international armed conflicts.
The practice collected gives examples in both international and non-international armed conflicts, while no practice was found suggesting ruses were prohibited in either type of conflict.
Ruses are acts intended to confuse the enemy. It is often stated that ruses are common in armed conflict. The UK Military Manual mentions the following examples of lawful ruses: surprises; ambushes; feigning attacks, retreats or flights; simulating quiet and inactivity; giving large strongpoints to a small force; constructing works, bridges, etc. which are not intended to be used; 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 uniforms of several different units so that prisoners and dead may give the idea of a large force; and 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.
 Lieber Code, Articles 15–16 and 101 (cited in Vol. II, Ch. 18, § 5); Brussels Declaration, Article 14 (ibid., § 6); Hague Regulations, Article 24 (ibid., § 2).
 Additional Protocol I, Article 37(2) (adopted by consensus) (ibid., § 3).
 See, e.g., the military manuals of Argentina (ibid., §§ 11–12), Australia (ibid., §§ 13–14), Belgium (ibid., §§ 15–16), Benin (ibid., § 17), Cameroon (ibid., § 18), Canada (ibid., §§ 19–21), Croatia (ibid., § 22), Ecuador (ibid., § 23), France (ibid., §§ 24–25), Germany (ibid., § 26), Indonesia (ibid., § 28), Israel (ibid., § 29), Italy (ibid., §§ 30–31), Kenya (ibid., § 32), Republic of Korea (ibid., § 33), Madagascar (ibid., § 34), Netherlands (ibid., §§ 35–36), New Zealand (ibid., § 37), Nigeria (ibid., §§ 38–39), South Africa (ibid., § 40), Spain (ibid., §§ 41–42), Sweden (ibid., § 43), Switzerland (ibid., § 44), Togo (ibid., § 45), United Kingdom (ibid., §§ 46–47), United States (ibid., §§ 48–50) and Yugoslavia (ibid., § 51).
 See, e.g., the statement of the United States (ibid., § 59); the practice of Iraq (ibid., § 55) and United States (ibid., § 59) and the reported practice of Algeria (ibid., § 54), Malaysia (ibid., § 56) and United Kingdom (ibid., § 57).
 Draft Additional Protocol II, Article 21(2) (ibid., § 4).
 See, e.g., Memorandum of Understanding on the Application of IHL between Croatia and the Socialist Federal Republic of Yugoslavia, § 6 (ibid., § 8); Agreement on the Application of IHL between the Parties to the Conflict in Bosnia and Herzegovina, § 2.5 (ibid., § 9); San Remo Manual, § 110 (ibid., § 10).
 See, e.g., the military manuals of Australia (ibid., § 13), Benin (ibid., § 17), Canada (ibid., § 21), Croatia (ibid., § 22), Ecuador (ibid., § 23), Germany (ibid., § 26), Italy (ibid., §§ 30–31), Kenya (ibid., § 32), Madagascar (ibid., § 34), Nigeria (ibid., § 38), South Africa (ibid., § 40), Togo (ibid., § 45) and Yugoslavia (ibid., § 51).
 Colombia, Constitutional Court, Constitutional Case No. T-303 (ibid., § 53).
 United Kingdom, Military Manual (ibid., § 46); see also the military manuals of Argentina (ibid., § 12), Australia (ibid., §§ 13–14), Belgium (ibid., § 15), Canada (ibid., § 20), Croatia (ibid., § 22), Ecuador (ibid., § 23), France (ibid., § 25), Germany (ibid., § 26), Hungary (ibid., § 27), Indonesia (ibid., § 28), Israel (ibid., § 29), Italy (ibid., § 31), Kenya (ibid., § 32), Republic of Korea (ibid., § 33), Madagascar (ibid., § 34), Netherlands (ibid., §§ 35–36), New Zealand (ibid., § 37), Nigeria (ibid., §§ 38–39), South Africa (ibid., § 40), Spain (ibid., §§ 41–42), Sweden (ibid., § 43), Switzerland (ibid., § 44), United Kingdom (ibid., § 47), United States (ibid., §§ 48–50) and Yugoslavia (ibid., § 51).

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 § 110
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 § 51