International Humanitarian Law

I. Introduction🔗

The scourge of sexual violence in conflict will continue until parties to armed conflict comply with its clear prohibition under IHL and provide adequate support services for survivors. This requires political will – deeds to accompany words.

Robert Mardini, ICRC Director-General1

International humanitarian law (IHL) ‘is a set of rules which seek, for humanitarian reasons, to limit the effects of armed conflict’.2 The rules governing IHL have been developed by States through the adoption of international treaties and the formation of customary international law. Modern-day IHL first came into being with the adoption of the original Geneva Convention in 1864. According to the International Committee for the Red Cross (ICRC, the ‘guardian’ of IHL),3 since then IHL ‘has evolved in stages, to meet the ever-growing need for humanitarian aid arising from advances in weapons technology and changes in the nature of armed conflict’. Following World War II, IHL was further codified in the four Geneva Conventions of 1949 and their two Additional Protocols of 1977, various conventions and protocols dealing with specific types of weapons used in warfare, and conventions aimed at ensuring respect for certain rights, such as children and cultural property, during armed conflict.4

The four Geneva Conventions and Additional Protocol I confer on the ICRC a specific mandate in the event of international armed conflict: ‘subject to the consent of the Parties to the conflict concerned’, the ICRC may ‘undertake humanitarian activities for the protection of wounded and sick, medical personnel and chaplains, and for their relief’.5 In the event of non-international armed conflict, the ICRC may similarly ‘offer its services to the Parties to the conflict’.6

Beyond direct humanitarian action, the ICRC is tasked with working for the understanding and dissemination of knowledge of IHL and preparing ‘any development thereof’.7 Where an obligation in this chapter is not extensively detailed under binding IHL, reference has accordingly been made to the Commentaries to the Geneva Conventions and other material that the ICRC has produced; while they constitute the ICRC’s interpretations, they nevertheless remain persuasive and offer avenues as to how States may fulfil their binding undertakings.

Note to reader
For more details on the role and powers of the ICRC, and on the enforcement mechanisms that may be available under IHL, consult the “Ratification and Enforcement of Treaties” chapter, “International Humanitarian Law” section.

I.1 CRSV under IHL🔗

As to the authoritativeness of the Customary IHL Study, see Marko Milanovic and Sandesh Sivakumaran, ‘Assessing the Authority of the ICRC Customary IHL Study: How Does IHL Develop?’ (2022) International Review of the Red Cross 1.

The Geneva Conventions and their Additional Protocols do not expressly use the term ‘sexual violence’ or ‘CRSV’. However, they do refer specifically to rape, enforced prostitution and ‘any form of indecent assault’,8 stipulate that persons taking no active part in the hostilities must be treated humanely,9 prohibit violence to person including cruel treatment and torture, and prohibit outrages upon personal dignity – all of which encompass sexual violence.10

Additional Protocol I, which applies to international armed conflicts (IAC) and is a part of customary international law, prohibits ‘outrages upon personal dignity, in particular humiliating and degrading treatment, enforced prostitution and any form of indecent assault’,11 as well as ‘rape, forced prostitution and any other form of assault.12

Article 4(2)(e) of Additional Protocol II, which is applicable to non-international armed conflicts (NIAC), prohibits ‘outrages upon personal dignity, in particular humiliating and degrading treatment, rape, enforced prostitution and any form of indecent assault’. However, the customary international law status of Additional Protocol II is contested and not all States are Parties. States that have not ratified Additional Protocol II are nevertheless bound by common article 3 of the Geneva Conventions, which implicitly prohibits sexual violence in a NIAC. It establishes an obligation of humane treatment and proscribes ‘violence to life and person, including mutilation, cruel treatment, torture and outrages upon personal dignity’.13

As a result, CRSV is clearly prohibited in both IACs and NIACs. While there are differences as to how the treaty prohibitions are formulated in IACs and NIACs, subsequent legal developments have recognised these prohibitions as customary law, applicable in both conflicts. This is crucial since the Additional Protocols are not as widely ratified as the Geneva Conventions. The International Court of Justice (ICJ) has highlighted that the fundamental tenets of IHL ‘are to be observed by all States whether or not they have ratified the conventions that contain them, because they constitute intransgressible principles of international customary law’.14

I.2 When Does CRSV Constitute a War Crime?🔗

To be considered a war crime under IHL, crimes such as CRSV require a nexus to an armed conflict. What constitutes a nexus is to be interpreted broadly. IHL ‘continues to apply in the whole territory of the warring States or, in the case of internal conflicts, the whole territory under the control of a party, whether or not actual combat takes place there’. It is sufficient that the alleged crimes were ‘closely related to the hostilities occurring in other parts of the territories controlled by the parties to the conflict’.15 In this sense, nexus should be understood as additionally covering acts that are not temporally and geographically close to the actual fighting.

War crimes need not have been planned or supported by some form of policy, but the existence of an armed conflict ‘must, at a minimum, have played a substantial part in the perpetrator’s ability to commit it, his decision to commit it, the manner in which it was committed or the purpose for which it was committed’.16 The perpetrator must have acted in furtherance of or under the guise of the armed conflict. To determine whether this is the case, some factors may be relevant:

  • The perpetrator is a combatant (combatants are ‘members of the armed forces of a party to the conflict’, ‘except medical and religious personnel’);17
  • The victim is a non-combatant;
  • The victim is a member of the opposing party;
  • The act may be said to serve the ultimate goal of a military campaign;
  • The crime is committed ‘as part of or in the context of the perpetrator’s official duties’.18

Nevertheless, civilians (i.e., ‘persons who are not members of the armed forces’)19 can commit war crimes:20 as long as the nexus requirement is met and the perpetrator has factual awareness of the armed conflict,21 IHL applies.

For there to be a nexus, an armed conflict must exist. IHL distinguishes between two types of armed conflicts, namely IAC, opposing two or more States deploying armed forces, and NIAC, between governmental forces and non-governmental organised armed groups, or between such groups only, resorting to protracted armed violence.22 An IAC exists as soon as a State uses armed force against another State with belligerent intent, regardless of the reasons for or intensity of the confrontation, and irrespective of whether a political state of war has been formally declared or recognised.23

The existence of a NIAC is subject to stricter requirements. Two criteria must be present – a certain degree of organisation among the parties, and a certain intensity of violence.24 To be organised, armed groups must possess a minimum level of organisation without which coordinated military operations and collective compliance with IHL would not be possible.25 While State armed forces generally satisfy this criterion, non-governmental armed groups are assessed under a series of indicative factors. These may be:

  • The existence of a command structure and disciplinary rules and mechanisms within the group;
  • The existence of a headquarters;
  • The fact that the group controls a certain territory;
  • The ability of the group to gain access to weapons, other military equipment, recruits and military training;
  • Its ability to plan, coordinate and carry out military operations, including troop movements and logistics;
  • Its ability to define a unified military strategy and use military tactics; and
  • Its ability ‘to speak with one voice and negotiate and conclude agreements such as cease-fire or peace accords’.26

The criterion of protracted armed violence means that the conflict must be distinguishable from internal disturbances and tensions such as ‘banditry, riots, isolated acts of terrorism, or similar situations’.27 It refers to the intensity of the armed violence, rather than its duration. Some indicative factors are:

  • The number, duration and intensity of individual confrontations;
  • The type of weapons and other military equipment used;
  • The number and calibre of munitions fired;
  • The number of persons and type of forces partaking in the fighting;
  • The number of casualties;
  • The extent of material destruction;
  • The number of civilians fleeing combat zones; and
  • The involvement of the UN Security Council.28
Note to reader
Since 2007, the Geneva Academy of International Humanitarian Law and Human Rights has maintained ‘The Rule of Law in Armed Conflicts’ project (RULAC), which is an ‘online portal that identifies and classifies all situations of armed violence that amount to an armed conflict under international humanitarian law (IHL). It is primarily a legal reference source for a broad audience, including non-specialists, interested in issues surrounding the classification of armed conflicts under IHL’.

Although IHL ‘applies from the initiation of such armed conflicts and extends beyond the cessation of hostilities until a general conclusion of peace is reached; or, in the case of internal conflicts, a peaceful settlement is achieved’,29 some obligations require action on the part of States already in peacetime. For example, this is the case with regard to IHL training and dissemination. Further, persons deprived of their liberty as a result of armed conflict remain protected by IHL until they have been released and repatriated or their status has otherwise been normalised, ‘if necessary even years after the end of the conflict’. Likewise, IHL remains applicable in territories ‘that remain occupied after the cessation of active hostilities until a political solution for their status has been found’.30

II. Legal Framework🔗

Note to reader
Because IHRL applies in armed conflict alongside IHL and, importantly, provides additional protection to conflict-affected persons, we recommend that readers refer to the “International Human Rights Law” chapter of the Guidebook to find a more detailed explanation of how human rights obligations complement IHL. See the Guidebook’s “Introduction” chapter for a discussion on the relationship between IHL and IHRL.

III. Obligations🔗


III.1 States must outlaw CRSV🔗

III.2 States cannot use restrictive language to define CRSV🔗

III.3 States must educate their population on CRSV🔗

III.4 States cannot apply the prohibition of CRSV discriminately🔗

III.5 Special protection against CRSV is owed to prisoners of war (POWs), detainees and internees🔗

III.6 Special protection against CRSV is owed to refugees, stateless persons and transferred persons🔗

III.7 Special protection against CRSV is owed to women81🔗

III.8 Special protection against CRSV is owed to children🔗

III.9 Special protection against CRSV is owed to persons with disabilities🔗

III.10 Special protection against CRSV is owed to population in occupied territory🔗

Justice and Accountability🔗

III.11 States must ensure victims/survivors of CRSV who have been deprived of their liberty (including POWs) have access to reporting procedures🔗

III.12 States must investigate and prosecute CRSV🔗

III.13 States must provide victims/survivors of CRSV with access to justice🔗

III.14 States must acknowledge that perpetrators of CRSV may be civilian or military🔗

III.15 States must distinguish between different modes of liability with regard to CRSV🔗

III.16 States must impose penalties that reflect the severity of CRSV🔗

Humanitarian Response🔗

III.17 States must provide victims/survivors of CRSV with appropriate care🔗


III.18 States must make reparations for CRSV🔗

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