Ukraine Symposium – Deception and the Law of Armed Conflict

As Ukraine continues to defend against Russian invasion, its armed forces are increasingly turning to deception operations to minimize their asymmetrical disadvantages with Russian forces. As part of the campaign to regain control of Kharkiv, for example, Ukraine’s forces employed mannequins strapped to trees and other cover wearing military fatigues and armed with fake rifles to “confuse attacking Russian forces.” While the decoys obviously look fake at close range, they have been “mostly effective against helicopters and aircraft” that engage forces from greater distances. In other areas, similar “scarecrow soldiers” armed with mock portable anti-aircraft missiles have also fooled Russian pilots wary of being shot down by Stinger missiles.

More recently, Ukraine has protected its High Mobility Artillery Rocket Systems (HIMARS) – high-value targets due to their impact on Russia’s combat operations – using wooden decoys to fool Russia into exhausting its cruise missile stocks. Because the inexpensive decoys are nearly indistinguishable from the real systems when spotted by Russian unmanned aerial vehicles, Russian warships are needlessly expending cruise missiles against them. Indeed, Russia has mistakenly “claimed to have hit more HIMARS than [the U.S. has] even sent.”

Such deception operations raise the issue of whether Ukraine is committing acts of perfidy prohibited by the law of armed conflict or conducting lawful ruses long permitted in war. This post provides a brief overview of how the law of armed conflict regulates military deception and explains why Ukraine’s use of mannequins and decoys is lawful.

Unlawful Deceptions Under the Law of Armed Conflict

Generally, parties to an armed conflict must observe the principle of “good faith” with their enemies (DoD Law of War Manual, § 5.21). Two notable deceptions that breach this rule of conduct are perfidy and misuse of distinctive emblems. While practitioners often conflate them because they both involve false pretenses, they are distinct violations. Russia and Ukraine are Parties to the 1907 Hague Convention IV’s Annexed Regulations, the 1949 Geneva Conventions, and their 1977 Additional Protocol I, which contain the relevant treaty law for both perfidy and misuse of distinctive emblems.

Perfidy

With respect to perfidy, Article 23 of the Annexed Regulations states that soldiers may not “kill or wound treacherously” the enemy. Seven decades later, Article 37 of Additional Protocol I refined this rule by replacing the term treachery with perfidy and including capture as a prohibited activity (see ICRC Commentary, ¶ 1488). It provides,

It is prohibited to kill, injure, or capture an adversary by resort to perfidy. Acts inviting the confidence of an adversary to lead him to believe that he is entitled to, or is obliged to accord, protection under the rules of international law applicable in armed conflict, with intent to betray that confidence, shall constitute perfidy.

As is apparent, the prohibition has multiple components. First, perfidy requires a false claim to protection under the law of war, such as those prescribed by the Geneva Conventions or Additional Protocol I (see U.S. DoD Law of War Manual § 5.22.1). A soldier placed hors de combat due to becoming wounded, for example, may not be made the object of attack (Geneva Convention I, art. 12). Feigning injury, therefore, would be a false claim to this protection (see AP I, art. 37(1)(b)). Similarly, wrongfully wearing a Red Cross, a distinctive emblem under the Geneva Conventions and Additional Protocol I, would be a false claim to the protections provided for personnel performing medical functions (see, e.g., Geneva Convention I, arts. 24, 25, 38, and 39).

Ukraine is not claiming its decoys are entitled to any international legal protections. Indeed, its claims are quite the opposite – armed forces and their artillery systems are undeniably military objectives liable to attack (see generally DoD Law of War Manual, § 5.6). Thus, the Ukrainian deception operations under consideration do not qualify as perfidy.

Next, an offender must intend to deceive by betraying the enemy’s confidence in the falsely claimed legal protection (see ICRC 1987 Commentary, ¶ 1500). In other words, the purpose of the false claim must be to exploit the particular status at issue. Feigning injury or misusing a distinctive emblem, for example, may “invite the enemy’s confidence” that the individual or object concerned enjoys protection under the law of armed conflict, but those acts would not constitute perfidy unless the offender commits them with an intent to leverage the enemy’s reliance on their respective protections.

While Ukraine’s forces are admittedly intending to deceive their enemy, they are not intending to betray Russians’ confidence in the rules of war. Accordingly, in addition to the absence of a false claim to legal protections, Ukraine’s actions lack the requisite intent to constitute perfidy.

Finally, the law of armed conflict does not proscribe all perfidious acts. Absent a causal nexus to killing, wounding, or capturing, it does not prohibit them (see ICRC 1987 Commentary, ¶¶ 1490–91). In this case, the intent is merely to cause the enemy to waste valuable resources and confuse its targeting analysis

Readers should note there is a “permanent controversy” surrounding this requirement because it provides a “considerable number of possibilities to indulge in perfidious conduct…not directly aimed at killing, injuring or capturing” the enemy (ICRC 1987 Commentary, ¶ 1492; see also Watts, pp. 144–47). It does not prohibit, for example, feigning an injury to escape the enemy during battle (DoD Law of War Manual, § 5.22.1.1). Further, it is unclear whether perfidy includes attempts to kill, wound, or capture (see ¶¶ 1491–95). Strictly construed, Article 37 does not proscribe failed attempts to achieve an intended result (see ¶ 1492; Watts, p. 146; but see ¶ 1493). Hague IV’s Annexed Regulations, on the other hand, expressly prohibit attempts to kill or wound (see Article 23).

The question of whether unlawful perfidy under customary law includes the act of capturing the enemy is not well-settled. In its Customary International Humanitarian Law study, the ICRC claims that the “killing, injuring, or capturing [of] an adversary by resort to perfidy is prohibited” (Rule 65). Thus, in its view, the customary prohibition mirrors Additional Protocol I, Article 37.

But some States that are not Parties to the Protocol, including the United States, argue that the prohibition has historically only applied to killing or wounding (see DoD Law of War Manual, § 5.22.2.1; Rule 65’s Commentary). For instance, the 1883 Lieber Code, which purported to codify customary practice, only condemned “clandestine or treacherous attempts to injure an enemy” (Article 101; see also 1874 Brussels Declaration, art. 13(b); 1880 Oxford Manual, art. 8(b)). This exclusion of capture is also consistent with the treatment of perfidy as a war crime under international criminal law (see Elements of Crimes, Rome Statute, art. 8(2)(b)(xi)). This debate is moot in the Russia – Ukraine conflict because both parties are bound by Article 37 of Additional Protocol I.

To summarize, Ukrainian forces are deliberately using deception to gain military advantages that could potentially lead to the death, injury, or capture of Russian troops. But, as explained above, they are not doing so “by resort[ing] to perfidy.”

Misuse of Emblems

In some cases, deception operations that do not qualify as perfidy are nevertheless unlawful on other grounds. Article 23 of Hague Convention IV’s Annexed Regulations forbids the “improper use” of the “distinctive badges of the [1906] Geneva Convention.” Additional Protocol I extends this proscription to “the distinctive emblem of the red cross, red crescent or red lion and sun or of other emblems, signs or signals provided for by the [1949 Geneva] Conventions or by this Protocol,” as well as to unauthorized use of the “distinctive emblem of the United Nations” (Article 38).

Customary international law contains similar prohibitions (see ICRC’s Customary International Humanitarian Law study, Rules 59, 60, 61). Although neither Article 23 nor Article 38 defines improper use, the term’s customary interpretation is “any use other than that for which the distinctive emblems were intended” (ICRC’s Customary International Humanitarian Law study, Rule 59). Thus, emblems may only be used to identify applicable personnel, equipment, or locations (see DoD Law of War Manual, § 5.24.2–6). To illustrate, the rule prohibits applying a red cross on a vehicle not exclusively used for medical purposes (see Rule 59; Geneva Convention I, arts. 35 and 39; DoD Law of War Manual, § 5.24.2). Thus, misuse of emblems condemns false claims to special legal protections provided by international humanitarian law.

In contrast to perfidy, however, the misuse of emblems is a per se law of war violation that does not require a particular result, such as killing, wounding, or capturing the enemy (see AP I, art. 38; ICRC’s Customary International Humanitarian Law study, Rules 59, 60, 61; see also DoD Law of War Manual, § 5.24). Returning to the example above, the rule prohibits applying a Red Cross to a non-medical military vehicle, even if forces are not using it to attack the enemy (see ICRC 1987 Commentary, ¶ 1532). But if the pretense deliberately results in the enemy’s death, injury, or capture, it constitutes both misuse and perfidy.

Regarding Ukraine’s mock soldiers and equipment, its forces are self-evidently not misusing any distinctive emblems. In fact, the use of HIMARS decoys is so effective because Russian troops are “invited” to target them as supposed military objectives. Ukraine is undoubtedly trying to fool Russia’s reconnaissance efforts, but not by abusing the legal protections afforded distinctive emblems.

Ruses and the Law of Armed Conflict

Ukraine’s forces may not be resorting to perfidy or misusing distinctive emblems, but they are intentionally misleading Russians in an effort to even the odds. Unlike perfidy and misuse, however, such “ruses of war” are permissible under longstanding rules of both treaty and customary international law (see, e.g., Hague IV’s Annexed Regulations, art. 24; ICRC’s Customary International Humanitarian Law study, Rule 57; DoD Law of War Manual, § 5.25.1). As stated in Additional Protocol I, 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 an adversary with respect to protection under that law.” (Article 37).

Although perfidy and ruses intend to confuse or mislead the enemy, ruses do not exploit an enemy’s good faith reliance on international legal protections (e.g., civilians, wounded and sick, emblems, etc.). Nor can the tricks ruses employ violate any other rules under the law of armed conflict (ICRC’s Customary International Humanitarian Law study, Rule 57; DoD Law of War Manual, § 5.25.1.2). For example, “although fighting in the enemy’s uniform would not be perfidy since enemy military personnel are not generally protected by the law of war, fighting in the enemy’s uniform also would not be a ruse, since such action would infringe upon the rule against improper use of the enemy’s uniform” (§ 5.25.1.2).

As the long lineage of these rules implies, militaries have commonly employed ruses throughout history for various purposes (see DoD Law of War Manual, § 5.25.1.1). For instance, to ensure the success of the D-Day invasion of Normandy during the Second World War, the Allies relied on surprise, camouflage to disguise forces, disinformation (e.g., Operation Bodyguard), false intercepts (e.g., Operation Mincemeat), a “Ghost Army” of inflatable tanks, and dummy paratroopers imitating an airborne assault (Operation Titanic), among other misleading tactics. In sum, forces may lawfully surprise, trick, confound, or mislead the enemy so long as such deceptions are not perfidious and do not otherwise violate the law of armed conflict.

The use of mannequins and wooden decoys to fool Russia’s forces are classic ruses. As illustrated by the DoD Law of War Manual, “inducing enemy forces to waste their resources” and “misleading the enemy as to the planned targets or locations of military operations” are textbook examples of lawful ruses intended to mislead the enemy or cause him to act recklessly (§ 5.25.1.1). Ukraine’s mannequins and scarecrows are “confus[ing] incoming [Russian] forces that might try to make a push” against Ukraine-controlled territory. Similarly, Russian forces are targeting wooden replicas they believe to be high-value HIMARS artillery systems that have devastatingly impacted their operations. As a result, they are expending valuable cruise missiles without success, thereby reducing their inventories for use against Ukraine’s actual forces.

Ukraine’s mannequins, scarecrows, and decoys are plainly lawful. But their success is also remarkable considering Russians traditionally pride themselves as masters of military deception, or what they call maskirovka. By confusing Russian forces using mannequins “likely scavenged from destroyed buildings,” Ukraine’s forces are ironically turning Russians’ favorite tactic against them.

Conclusion

Ukraine’s use of HIMARS decoys to trick Russian forces into wasting its missile inventory is a classic example of a lawful ruse of war. Unlawful perfidy prohibits using international law’s protections as a sword instead of a shield. It requires a false claim to protections under the law of war that results in the enemy’s death, injury, or – if Additional Protocol I applies – capture. Ukraine’s deceptions do not implicate these requirements, nor do they violate any other provisions of the law of armed conflict. Accordingly, Ukraine’s use of decoys is permissible under international law.

***

Major William C. Biggerstaff is a military professor at the Stockton Center for International Law at the U.S. Naval War College, where he co-teaches a course on the Law of Armed Conflict.

Photo credit: Airman 1st Class Jonathan Valdes Montijo, U.S. Air Force