SEXUAL VIOLENCE IN INTERNATIONAL CRIMINAL LAW: THEORIES FOR PROSECUTING CO-PERPETRATORS
By Susannah Walton
International law and the prosecution of war crimes is an important topic in today’s political climate. With many conflicts ongoing, looking towards international legal solutions is appealing. In war-time conflict, a common occurrence is the crime of sexual violence. Sexual violence has long-term effects. The emotional pain can burden individuals and communities long after the conflict has subsided.
While the effects of sexual violence are substantial, it has only recently been recognised as an international crime. Due to the criminal tribunals of the 1990s, and the establishment of the International Criminal Court (ICC), international criminal law saw swift advancement. The ICC identified sexual violence as a crime in international law and the tribunals sought to prosecute war crimes including sexual violence. International law faced the complication that there can be multiple parties at fault for war crimes: civilians, military officials, paramilitaries, rebel groups and, oftentimes, members of government. The key issue, not only for crimes of sexual violence but also for international criminal law generally, is who should be held responsible when war crimes have taken place?
A significant outcome of international criminal tribunals has been the development of theories for holding senior ranking officials in government and military positions responsible for crimes. The indictments for senior officials included charges of crimes of sexual violence. Jurisprudence from these tribunals has demonstrated that the prosecution’s approach needs to be flexible and adaptable to the circumstances of each case. Current conflicts in the world are reporting sexual violence occurring. It is therefore important for future prosecutions to implement successful strategies from previous criminal tribunals when it comes to the complicated process of prosecuting sexual violence.
HISTORICAL PROGRESS OF INTERNATIONAL RECOGNITION FOR SEXUAL VIOLENCE
Sexual violence occurs when a sexual act is imposed on a person without that person’s free consent. This is a broad definition that includes many acts of sexual violence. Historically, the use of sexual violence can be traced to ancient times of warfare and is not considered a modern day outcome of war.
Turning to recent history, two of the most significant international criminal trials following the end of World War II were the International Military Tribunals (IMT) in Nuremberg and Tokyo. These were a step forward for the progress of international criminal law as state officials were prosecuted in an international ad hoc setting rather than in national jurisdictions. However, it has been stated that a failing of the IMT tribunals was that the IMT Charter failed to include the prosecution of sexual violence. This exclusion occurred despite the existence of sexual violence being noted in criminal proceedings. Rape, sexual torture and forced sterilisation were documented in transcripts, yet in most cases there were no charges for convicting crimes of sexual violence.
A more significant step towards the prosecution of sexual violence in international criminal law occurred when the Rome Statute in 2002 established the ICC. The creation of the ICC established many crimes as being violations of international criminal law, one of which was sexual violence. Sexual violence was codified into a crime committed in international law in the ICC’s Statute in the Crimes Against Humanity section, Article 7(g). This Statute allows for many forms of sexual violence to be prosecuted by the ICC and embeds in international codified law that sexual violence is an international crime. While the ICC has not been signed by every state and arguably has limitations, the recognition of sexual violence as an international crime is an important step forward for future prosecutions of sexual violence.
Additional progress and codification in international law in the past three decades have taken place in the form of the International Criminal Tribunal for the former Yugoslavia (ICTY) as well as the International Criminal Tribunal for Rwanda (ICTR). The ICTY in its initial investigations outlined its intention to prosecute sexual violence that had taken place in the former Yugoslavia. In UN Security Council Resolutions during the conflict, it was noted that a growing concern for violations of international law included crimes of sexual violence. In UN Resolution 827 it states “organized and systematic detention and rape of women” were among the many continuing reports causing alarm and there were “flagrant violations of international humanitarian law”. In the ICTY and ICTR Statute Articles under “Crimes Against Humanity”, rape is listed as a violation of international law.  Codification of sexual violence has allowed the tribunals to bring forward cases involving sexual violence, and convictions made for those who have either committed these crimes or failed to prevent them.
In comparison to historical perspectives on crimes of sexual violence and previous international prosecutions, the ICTY and ICTR have made progress in firstly recognising sexual violence as an atrocity of war, and secondly to prosecute it as an international crime. In the Prosecutor v Dusko Tadic, an inmate held at a detention camp describes the impact of sexual violence:
The act of rape… had a terrible effect on them. They could, perhaps explain it to themselves when somebody steals from them, or even beatings or even some killings. Somehow they sort of accepted it in some way, but when the rapes started they lost all hope. Until then they had hope that this war could pass, that everything would quiet down. When rapes started, everybody lost hope, everybody in the camp, men and women. There was such fear, horrible.
As this quote highlights, the atrocities of sexual violence should not be ignored. The ICTY and ICTR recognition of sexual violence will not erase the crimes committed, but will bring to light the violence and gross impact of the nature of these crimes.
APPROACHES OF THE ICTY AND ICTR
The ICTY and ICTR Statutes list sexual violence as a crime against humanity. In addition, the tribunals have sought various approaches to tackling issues with the prosecution of sexual violence. Article 1 of both the ICTY and ICTR Statutes specify that the jurisdictional approach of the tribunal will only concern allegations that are serious violations of international humanitarian law (IHL). The prosecution for crimes of sexual violence demonstrates that sexual violence is considered one of these serious violations. This confirmed a change in attitude from that which previously existed in international criminal law.
The ICTY/ICTR form of prosecution has strived to be flexible in its approach following the intentions outlined in Article 1. In two key cases: Akayesu (ICTR) and Kunarac (ICTY), the prosecution teams had varied approaches in holding higher-level officials accountable. For example, the crime of genocide in the ICTY/ICTR Statutes cite, verbatim, Article II of the Genocide Convention of 1948 and list multiple offences which involve “intent to destroy in whole or in part” a group of specific people. In the ICTR case Akayesu, the Trial Judgement found that rape or other forms of sexual violence fell within the definition of genocide and could be prosecuted as such. Considering sexual violence to be an act of genocide (which is widely considered the gravest of all international crimes) was a significant decision for the trial chamber. This verified the willingness of the prosecution team, as well as the trial chambers, to give serious weight and consideration to crimes of sexual violence.
In comparison, in the ICTY case Kunarac the accused was charged under Article 3 of the ICTY Statute for rape related charges. Article 3 is a charge for violations of the laws or customs of war. This includes employment of poisonous weapons, wanton destruction of cities, devastation not justified by military necessity, etc. In the appeal decision in Kunarac, the Appeal Chambers found that rape as a charge under Article 3 was entirely relevant to the circumstances of the case. Like Akayesu, Kunarac demonstrated the ability of the international criminal tribunals to prosecute sexual violence as a serious violation of international law by approaching the case in a tactical way. These cases highlight the courts’ acceptance of the gravity of sexual violence, and the severity of the crime within the context of war.
In addition to the flexible approach for prosecuting the crime of sexual violence, the next approach to consider is how the international criminal tribunals charge individuals. The jurisdictional approach in the ICTY/ICTR has been to indict senior ranking officials over lower level offenders. This has at times complicated prosecuting sexual violence. As Michelle Jarvis and Elena Martin Salgado write in Future Challenges to Prosecuting Sexual Violence Under International Law:
The revised mandate has highlighted the general challenges associated with holding senior figures responsible for crimes. Very often it is obvious that a massive campaign of crimes have been directed, or at least tolerated, by the senior political and military figures. However, proving culpability to exacting criminal law standards may not be easy. These cases frequently depend on a large and complex web of circumstantial evidence and the inferences that can be reasonably drawn from this evidence.
To prove criminal liability for senior ranking officials, international legal theory has adopted the practice of prosecuting offenders as co-perpetrators. Sexual violence is prosecuted under the theory of co-perpetration because the crimes committed were conspired in not only by sole individuals but also by groups of military officers and officials in government. This occurs through either instigating the setting-up of prisoner war camps, or through failure to prevent the crime of sexual violence from occurring. Prosecuting individuals jointly has therefore been a strategy for a wide range of crimes in the tribunals. The theory of Joint Criminal Enterprise (JCE) is an example of this approach. JCE occurs where there is (i) a plurality of persons; (ii) a common objective which amounts to or involves the commission of a crime within the governing statute; and (iii) the accused participates in the crimes or the objective’s implantation.
At the ICTY/ICTR, sexual crimes have been prosecuted using the theory of JCE, despite various complications. Complications can include a lack of physical evidence and problems with witnesses/victims being reticent to testify. This impedes the prosecution’s ability to evidentially show that attacks were not isolated incidents, but were widespread assaults tolerated or instigated by superior officials. Although there have been obstacles, the tenacity of prosecution teams have led to successful outcomes for prosecution of sexual violence under co-perpetrator theories.
For the purpose of this article, the approach of the ICTY will be analysed in relation to JCE convictions in sexual violence cases.
ICTY APPROACH TO CO-PERPETRATION
Sexual violence cases add a complex element to already logistically challenging casework. The ICTY prosecution has sought to demonstrate that attacks are systematic and widespread and not simply isolated incidents or consequences of war. The degree of how widespread sexual violence needs to be is varied and there does not need to be a specific level or specific threshold of evidence that must be reached to prove attacks are systematic. Each case stands on its own individual merits and circumstances.
The theory of ‘superior responsibility’ in international law, alongside JCE theories, has led to the pursuit of convictions for higher-ranking officials and has been used to demonstrate the widespread nature of attacks. Superior responsibility can apply in sexual violence cases where a superior failed to prevent or punish a subordinate for crimes committed. Challenges have existed under this approach for sexual violence cases. It is often difficult for the prosecution to prove intent and knowledge of an existing risk of sexual violence. While there has not been wide-ranging success under this theory, it should be noted that it is still an important strategy for international humanitarian law, as it demonstrates that superior officers will be held accountable for tolerance of sexual violence carried out by subordinates.
A more efficient and successful approach to prosecuting sexual violence appears to be JCE theory. According to Jarvis and Salgado:
[T]here is no reason to treat JCE cases where the crime-base includes sexual violence crimes differently from other JCE cases. No matter what types of crimes are involved, the key issue is always to link the crimes on the ground with the high-level accused person who may be physically removed from them. 
As with any other JCE case that the ICTY or other international tribunals/courts have prosecuted, linkage must be established for sexual violence cases. Jarvis and Salgado note that the first step is to prove that sexual violence was a part of the common criminal plan or purpose of which the accused in the JCE either participated in, or could foreseeably see sexual violence occurring. 
There is often a failure to establish how crimes of sexual violence fit into the overall behaviour of war crimes committed. It is difficult to substantiate that they did in fact form a part of the common criminal purpose for a JCE conviction. This is problematic for the prosecution teams, as demonstrating that sexual violence crimes formed a part of the common criminal purpose is a vital link to prosecuting senior officials for such crimes.
The Yugoslavian war is an example of the prevalence of sexual violence in war-time conflicts. The widespread occurrence of sexual violence affected many people during the decade-long war. If superior ranking officials are not held responsible for sexual violence that has taken place under their command, it amounts to an injustice for the victims who have suffered from these crimes. It is important that the prosecution establish that sexual violence is a foreseeable and, at times, direct outcome of conflict.
SUCCESS WITH JCE THEORY
A successful approach for prosecutors in JCE prosecutions of sexual violence will demonstrate that it is a “natural and foreseeable consequence” of war-time conflicts. This approach is what is known as JCE III. Foreseeability of sexual violence must be proven for a conviction to be successful under JCE III. While it is a disputed form of prosecution, there have been successful prosecutions at the ICTY for crimes of sexual violence using this theory.
Showing that sexual violence is a natural and foreseeable consequence of war challenges the belief that sex crimes exist in isolation and are the sole responsibility of the individual . JCE III establishes that superiors ordering acts of war arguably can foresee that their subordinates will carry out illegal and atrocious acts of violence on civilian and non-civilian populations. If the prosecution can prove that sexual violence is a foreseeable outcome of war, then actions that are taken by superiors to either incite violence or fail to prevent it can provide a clearer picture of liability to trial chambers. As stated by Goy, Jarvis and Pinzauti:
Theories of co-perpetration (such as JCE) are important legal tools for investigators and prosecutors in contextualizing sexual violence in conflict. Not only do they provide an effective framework for demonstrating the connection between sexual violence and the objectives of a criminal campaign, but they are generally among the most serious forms of criminal responsibility, leading to maximum accountability 
In prosecuting under the JCE III theory, ICTY prosecutions have demonstrated that foreseeability or a heightened risk of sexual violence is sufficient to meet the requirements of JCE III . This establishes that there is a high accountability for superior officials (military or government) to prevent, and not incite the use of sexual violence as a tool of warfare.
Like most theories and approaches to prosecution at the ICTY, there has been a learning curve of development. International criminal law is a relatively new branch of criminal law that has adapted theories from multiple national jurisdictions, as well as developing its own theories of criminal proceedings. JCE III has therefore not always been successful in prosecuting sexual violence.  It is not a definite form of prosecution, and will not suit every case of sexual violence. However, JCE theory of co-perpetration, particularly JCE III, demonstrates that there are many options for those prosecuting crimes of sexual violence. There is not one single uniform theory or mode of prosecution that can be applied homogenously to every case of sexual violence. Instead, there needs to be continuous flexibility. Like most criminal cases at the ICTY, facts and circumstances of each case are weighed and given contextual analysis and then applied to the issues at hand.
Overall, JCE III appears to have more widespread ability to apply to a broader range of cases. Going forward, JCE III could be used as a key tool for future prosecutions that include elements of sexual violence.
International law is not an easy avenue for criminal law. Political differences and international relations often create barriers to successful proceedings. Prosecuting sexual violence has arguably quite a few complications already working against it due to the nature of the crime itself.
Having adaptable processes such as theories of co-perpetration like JCE theory allows there to be a variety of choices for prosecuting crimes of sexual violence. This is of value for today’s political climate. For example, the United Nations General Assembly (UNGA) has stated that there will be an international criminal investigation into the conflict in the Syrian Arab Republic.  As noted in UN reports,  there have been acts of sexual violence that have taken place since the outbreak of the Syrian War in 2011. These violent acts are ongoing, widespread and systematic. International law needs to be assertive and adopt past approaches to prosecuting sexual violence, as cases like the Syrian War begin to be investigated and eventually prosecuted. 
International criminal tribunals’ work for prosecuting sexual violence has demonstrated that flexibility is vital to holding those accused accountable for sexual violence. International law has made progress in prosecuting sexual violence as an international crime. Going forward, reliance on previous international criminal tribunals’ work is imperative for the development of international criminal law. The work of the ICTY, as well other international criminal tribunals, form an essential legacy for international criminal law. It is important for the victims of sexual violence to see that their pain and suffering has been recognised, and consequently that those responsible are punished. Bearing this in mind, prosecution teams should look to past theories and strategies of co-perpetration to indict and charge those accused in cases of sexual violence.
Convicting sexual violence in international criminal law will hopefully give a sense of peace and justice to those who have suffered from these criminal actions, and demonstrate that it will not be tolerated or ignored by the international community.
* LLB Graduate (University of Edinburgh) (2017).
 United Nations, Security Council Report S/2015/203 (23 March 2015) available at: http://www.securitycouncilreport.org/atf/cf/%7B65BFCF9B-6D27-4E9C-8CD3-CF6E4FF96FF9%7D/s_2015_203.pdf; Human Rights Watch, UN: Sexual Violence a ‘Tactic of War’ Secretary General’s Report Highlights Rape, Sexual Slavery, Forced Marriage (14 April 2015) available at: https://www.hrw.org/news/2015/04/14/un-sexual-violence-tactic-war.
 UNICEF, Sexual violence as a weapon of war, available at: https://www.unicef.org/sowc96pk/sexviol.htm.
 Especially the International Criminal Tribunal for the former Yugoslavia (ICTY) and the International Criminal Tribunal for Rwanda (ICTR).
 Centres for Disease Control and Prevention, Sexual Violence: Definitions (22 March 2017) available at: https://www.cdc.gov/violenceprevention/sexualviolence/definitions.html; See also UN definition of sexual violence in UNSC Report S/2015/203 para 2.
 A M de Bouwer, “Interdisciplinary Approaches to Recognizing, Investigating and Prosecuting Sexual Violence as an International Crime”, in AM de Bouwer, C Ku, R Romkens and L van den Herik (eds), Sexual Violence as an Interdisciplinary Crime: Interdisciplinary Approaches (2013) at 3; K Askin, “Treatment of Sexual Violence in Armed Conflicts: A Historical Perspective and the Way Forward”, Sexual Violence as an Interdisciplinary Crime: Interdisciplinary Approaches (2013) at 21 – As mentioned in Askin’s analysis, criminal codes as far back as 500 BC mention conduct that would be found in violation of wartime practice. Cicero himself discussed wartime practice and rules of conduct that should be observed in times of war. Askin describes, in ancient civilisations the act of rape was considered a violation of property, as women were considered the property of men and therefore the violation of a women was a crime founded in property law; K Askin, Interdisciplinary Approaches at 25 – Furthermore, in Askin’s analysis codified laws of war on gender related crimes began to develop more fully in the late eighteenth and nineteenth centuries. While vague, there was more mention of protection of women and children and the violation of molestation of their person.
 Askin (n 6) at 32.
 Ibid.; See UN Report Outreach Programme on the Rwanda Genocide and the United Nations, “Background information on Sexual Violence used as Tool of War” Department of Public Information (March 2014) available at: http://www.un.org/en/preventgenocide/rwanda/about/bgsexualviolence.shtml
 Askin (n 6) at 33, 37 – While there was no concrete prosecution of sexually violent crimes in the IMT Tribunals, Askin submits that the mention of it still has significance and importance for progress in international criminal prosecution, and while it can be easily criticised, it still marks some of the beginning steps of jurisprudential evidence towards prosecuting sexual violence as a violation of international law.
 Ibid. at 38-40 – Askin notes that in Tokyo there were charges/convictions of rape despite the fact that the charges were not included in the International Military Tribunal for the Far East (IMTFE) Charter.
 R Cryer, “International Criminal Law”, in M Evans (ed), International Law, 4th edn (2014) at 758.
 Rome Statute of the International Criminal Court 2002 Art 7(g).
 For a general discussion on the jurisdictional capabilities of the ICC see D Akande, “The Jurisdiction of the International Criminal Court over Nationals of Non-Parties: Legal Basis and Limits” (2003) 1 Journal of International Criminal Justice 618.
 de Bouwer (n 6) at 4.
 Security Council Resolution 808, 22 February 1993; Security Council Resolution, 827 May 1993.
 Security Council Resolution 827 was the document establishing the creation of the ICTY tribunal; UN ICTY, “The Tribunal – Establishment” available at: http://www.icty.org/en/about/tribunal/establishment.
 Security Council Resolution, 827 May 1993 at 1.
 ICTY Statute Article 5; ICTR Statute Art 3.
 Prosecutor v Dusko Tadic, IT-94-I-T, 7 May 1997 at para 175, available at: http://www.icty.org/x/cases/tadic/tjug/en/tad-tsj70507JT2-e.pdf.
 ICTY Statute Art 1; M Jarvis and E M Salgado, “Future Challenges to Prosecuting Sexual Violence under International law: Insights from ICTY Practice” in Interdisciplinary Approaches at 104.
 G Harbour, “International Concern Regarding Conflict Related Sexual Violence in the Lead-up to the ICTY’s Establishment” in S Brammertz and M Jarvis (eds), Prosecuting Conflict-Related Sexual Violence at the ICTY (2016) 28-29.
 Cryer (n 11) at 759; Prosecutor v Akayesu, ICTR-96-4 Trial Judgement (2 September1998) para 751.
 Prosecutor v Kunarac et al, IT-96-23 & IT-96-23/1-A, June 2002 (Kunarac Appeal Judgement), para 190; Jarvis and Salgado (n 20) at 104.
 Ibid. at 106.
 Ibid. at 107.
 B Goy et al, “Contextualizing Sexual Violence and Linking it to Senior Officials”, in S Brammertz and M Jarvis (eds), Prosecuting Conflict-Related Sexual Violence at the ICTY (2016) at 259 and 261.
 Ibid. at 221.
 Ibid. at 222.
 M Marcus, “Investigation of Crimes of Sexual and Gender-Based Violence under International Criminal Law”, Interdisciplinary Approaches at 213; For protection of witnesses has been established for victims of sexual violence, see ICTY Statute Art 22; Harbour, Prosecuting Conflict- Related Sexual Violence at 29.
 Prosecutor v Broanin, IT-99-36-A, 3 April 2007 (Appeal Judgment) para 256-257; Jarvis and Salgado (n 20) at 108.
 Marcus (n 28) at 212.
 Jarvis and Salgado (n 20) at 108-11.
 Goy et al (n 26) at 241; Applies to superiors at every level of ranking – i.e. de jure or de facto.
 Prosecutor v Delic et al, IT-96-21-A, 20 February 2001 (Celebici Appeal Judgement) para 238; Milutinovic et al, IT-05-87-T, 26 February 2009 (Milutinovic Trial Judgement), vol III, paras 472, 1135; Jarvis and Salgado (n 20) at 108-109.
 Goy et al (n 26) at 242 – For discussion on modes of liability relating to Art 7(1), as well as what the prosecutions must prove to successfully convict someone under superior responsibility.
 Ibid. at 242.
 Jarvis and Salgado (n 20) at 110 – While factors as noted by Jarvis and Salgado such as separation of men from women in detainment camps, failure of monitoring by superior officers, or other forms of detention in furthering prosecution for superior responsibility in sexual violence cases can be helpful, it requires a significant amount of resources and investigatory work. In particular, proving a specific risk in an area that sexual violence would have occurred due to the nature of attacks, type of detainment, and other factors previously mentioned can be difficult to prove.
 Ibid. at 111.
 Goy et al (n 26) at 242.
 Prosecutor v Krajisnik, ICTY-00-39-T (Appeal Judgement) (n 38) paras 175-8; Goy et al (n 26) at 227.
 M L Hirsch, “Women Under Siege: Bosnia” Womens Media Centre (8 February 2012) available at: http://www.womenundersiegeproject.org/conflicts/profile/bosnia – Numbers of sexual violence are difficult to approximate correctly as many incidents often go unreported, and due to the fact that Bosnia, and other conflict zones in Yugoslavia were economically and politically destroyed following the end of the war, many individuals who were affected fell under the radar.
 Goy et al (n 26) at 228.
 Jarvis and Salgado (n 20) at 113.
 Goy et al (n 26) at 229.
,J D Ohlin , “Joint Intentions to Commit International Crimes” (2011) Cornell Law Faculty Publications, at 705-706, 169 available at: http://scholarship.law.cornell.edu/facpub/169 – JCE as an international legal theory proves to be difficult within criminal law standards to prosecute because it is difficult to demonstrate culpa for an individual who does not have exact intent of committing a crime. The difficulty is to assess whether or not the accused foreseeably knew from an objective standard that a criminal act would occur.
 Jarvis and Salgado (n 20) at 114-116; Prosecutor v Krstic, IT-98-33-T, 2 August 2001 (Krstic Trial Judgement); See Pavkovic conviction in the Miluntinovic Trial Judgement.
 Goy et al (n 26) at 229.
 Ibid. at 221.
 Ibid. at 260.
 In the Miluntinovic case, while the accused Pavkovic was prosecuted under JCE III crimes, the majority of the co-conspirators were acquitted of sexual violence responsibility: see Miluntinovic Trial Judgement vol III, paras 472, 1135; See Goy et al, for Judge Chowhan’s partial dissent vol 111; Jarvis and Salgado (n 20) at 117.
 UN General Assembly, A/71/L.48 (19 December 2016) available at: http://www.un.org/ga/search/view_doc.asp?symbol=A%2F71%2FL.48.
 UN Women, “We just keep silent” (April 2014) available at: http://uniraq.org/images/documents/We%20Just%20Keep%20Silent%20final%20English.pdf.
 Goy et al (n 26) at 258-261 for concluding thoughts on best practices for prosecuting crimes of sexual violence.