Perfidy and ruses of war

== Definition ==
Perfidy and ruses of war
The prohibition of perfidy, as defined in AP I, covers the killing, injuring or capturing of an adversary by resort to 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.Art 37(1) AP I. Although the prohibition is generally understood to exist also under customary international law, not all of its elements are universally considered to have crystallized into custom. In particular, opinions diverge on whether the customary prohibition covers capturing enemy personnel: for example, the US takes the narrower view that it does not,US DoD Law of War Manual, para 5.22.2 (“It may not be prohibited to invite the confidence of the adversary that he or she is obligated to accord protection under the law of war, for certain purposes (e.g., to facilitate … capturing enemy personnel … )”). while the ICRC has taken the opposite broader view.ICRC CIHL Study, rule 65.
Accordingly, in order for a cyber operation to qualify as prohibited perfidy under customary international law, it must simultaneously meet the following four conditions:
# The operation must relate to a protection enjoyed by a particular person, object or activity, that is specifically provided for in IHL (i.e., protection afforded on the basis of moral considerations, or norms of other bodies of law does not suffice);Waldemar A Solf, ‘Article 37: Prohibition of Perfidy’ in Bothe et al (eds), New Rules for Victims of Armed Conflicts (Brill 1982) 235–36; ICRC CIHL Study, commentary to rule 65, at 224 (“the definition of perfidy provides that the confidence of an adversary be based on a situation which requires protection under international humanitarian law”) (emphasis added).
# The operation must invite the confidence of the adversary that he or she is entitled to, or must accord, protection under IHL;Yves Sandoz, Christophe Swinarski and Bruno Zimmermann (eds), Commentary on the Additional Protocols of 8 June 1977 to the Geneva Conventions of 12 August 1949 (ICRC 1987) 435 para 1500; ICRC CIHL Study, commentary to rule 65, at 223 (“The essence of perfidy is … the invitation to obtain and then breach the adversary’s confidence”) (emphasis added).
# The perpetrator must intentionally betray the confidence of the adversary;See, eg, Elements of Crime to the Rome Statue, Art 8(2)(b)(xi) and Art 8(2)(e)(ix) (war crime of treacherously killing or wounding); Yves Sandoz, Christophe Swinarski and Bruno Zimmermann (eds), Commentary on the Additional Protocols of 8 June 1977 to the Geneva Conventions of 12 August 1949 (ICRC 1987) 435 para 1500; ICRC CIHL Study, commentary to rule 65, at 223 (“The essence of perfidy is … the invitation to obtain and then breach the adversary’s confidence”) (emphasis added).
# The act must result in the prohibited effect of the adversary’s death or injury (or for the proponents of the broader view above, capture).Compare US DoD Law of War Manual, para 5.22.2 (“It is prohibited to use perfidy to kill or wound the enemy.”) with ICRC CIHL Study, commentary to rule 65, at 225 (“killing, injuring or capturing by resort to perfidy is illegal under customary international law”). Cyber operations, the effect of which only occurs in cyberspace or is limited to damaging or destroying material property, are not covered by the prohibition.Cf. Waldemar A Solf, ‘Article 37: Prohibition of Perfidy’ in Bothe et al (eds), New Rules for Victims of Armed Conflicts (Brill 1982) 234 (“sabotage or the destruction of property as such, through the use of perfidious deception is not prohibited by this article”); Humanitarian Policy and Conflict Research, Manual on International Law Applicable to Air and Missile Warfare (CUP 2013) rule 111(a), commentary para 7 (“A clear example of perfidious action which is not prohibited as ‘perfidy’ under customary international law or under AP/I, is the destruction of property”); Tallinn Manual 2.0, rule 122, commentary para 10 (“The perfidy Rule does not extend to perfidious acts that result in damage or destruction of property.”). 
The prohibition of perfidy applies in both international and non-international armed conflicts.ICRC CIHL Study, rule 65; Humanitarian Policy and Conflict Research, Manual on International Law Applicable to Air and Missile Warfare (CUP 2013) rule 111(a), commentary para 11; Tallinn Manual 2.0, rule 122, commentary para 1; see also Rome Statute, Article 8(2)(e)(ix) (providing that “killing or wounding treacherously a combatant adversary” constitutes a war crime in non-international armed conflicts). 
Cyber operations which rely on deception to mislead the adversary, but which do not infringe any rule of IHL nor do they invite the confidence of the adversary with respect to protection under IHL, qualify as lawful ruses of war.Art 37(2) AP I; ICRC CIHL Study, rule 57. See also Art 24 Hague Regulations (“Ruses of war … are considered permissible.”). Ruses of war are considered a permissible method of warfare and include the use of camouflage, decoys, mock operations, and misinformation.Art 37(2) AP I; ICRC CIHL Study, rule 57.
== Appendixes ==
=== See also ===
* Scenario 15: Cyber deception during armed conflict
=== Notes and references ===
=== Bibliography and further reading ===
Category:Perfidy and ruses of war
Category:Means and methods of cyber warfare
Category:International humanitarian law
Category:Legal concepts