From: Oxford Public International Law (http://opil.ouplaw.com). (c) Oxford University Press, 2023. All Rights Reserved.date: 06 February 2023
- Civil and political rights — Economic, social, and cultural rights — Gross violations — Crimes against humanity — Geneva Conventions 1949
Published under the auspices of the Max Planck Institute for Comparative Public Law and International Law under the direction of Professor Anne Peters (2021–) and Professor Rüdiger Wolfrum (2004–2020).
1 The idea that some elementary principles of humanity should be adhered to in all circumstances, including during armed conflicts, has surfaced at various times throughout history (see also Civilian Population in Armed Conflict; Humanitarian Law, International). During the past century, the unprecedented massive scale of crimes aimed at degrading whole categories of victims and perpetrated as part of the policy of States or State-like structures has gradually led to the recognition under international law of ‘crimes against humanity’ (see also International Criminal Law). Indeed, the notion that certain crimes shock the conscience of all nations and of humankind as a whole has constituted the philosophical underpinning of crimes against humanity from their inception. Recognizing the unacceptability of impunity for crimes that defy universal values of international human rights on such a massive scale, the international community has gradually shifted from the traditional paradigm whereby international law refrained from imposing obligations on individuals (see also Individuals in International Law). This shift is premised on the acknowledgement that States and other subjects of international law ultimately act through individual persons.
2 The term ‘crimes’ refers to the gravity of the acts committed, which demands penal sanction. The other term, ‘humanity’, may be understood as referring to humankind, to the characteristic of being ‘human’, or even to the feelings of humanness or compassion supposedly shared by all men and women. In any event, due to its evocative nature the expression has undoubtedly taken hold not only in legal discourse, so much so that various types of large-scale criminal behaviour are often, though imprecisely, denominated as ‘crimes against humanity’.
B. Early Developments
3 The 1899 Hague Convention respecting the Laws and Customs of War on Land (‘1899 Hague Convention II’; see also Hague Peace Conferences [1899 and 1907]) was the first international legal instrument enshrining the principle of humanity with respect to armed conflicts: it stated that ‘[u]ntil a more complete code of the laws of war is issued … populations and belligerents remain under the protection and empire of the principles of international law, as they result from the usages established between civilized nations, from the laws of humanity, and the requirements of the public conscience’ (Preamble 1899 Hague Convention II, the so-called Martens Clause). The aim of this clause was to substitute principles of humanity for the unlimited discretion of the military commander. It therefore clearly applied exclusively to situations of armed conflicts (see also Warfare, Methods and Means).
4 Despite previous vague references to ‘crimes against humanity’, the expression was apparently first used in relation to individual criminal responsibility only in May 1915, when France, Great Britain, and Russia declared with respect to the massacre of Armenians that they would hold personally responsible all persons implicated in these ‘new crimes of Turkey against humanity and civilization’ (United States [‘US’] Department of State Papers relating to the Foreign Relations of the United States 1915, Supplement [US Government Printing Office Washington 1928] 981). However, this expression did not find its way into the 1923 Treaty of Lausanne between the Allied Powers and Turkey (Lausanne Peace Treaty ). The US government’s opposition also prevented the inclusion of crimes against humanity in the report of the Commission on the Authors of the War and on the Enforcement of Penalties to the Versailles Peace Conference (La Conférence de la paix et la Société des Nations Responsabilités des auteurs de la Guerre et Sanctions [Les éditions Internationales Paris 1930]). The report did, however, mention war crimes.
C. Nuremberg and Beyond
5 During World War II, the Allied Powers decided that high-level enemy officials should be tried for crimes committed during the conflict. They quickly realized, however, that some of the worst acts perpetrated, in particular by German officials, had not been committed against foreign nationals, but rather against Germany’s own citizens on racial, political, or other discriminatory bases. They could therefore not be considered criminal under the then-applicable laws or customs of war. Thus, the London Agreement embodying the Charter of the International Military Tribunal (‘IMT Charter’) for the trial of major war criminals of the European Axis included a provision on crimes against humanity (see also International Military Tribunals; International Military Tribunal at Nuremberg [IMT]). RH Jackson, head of the American delegation and Chief of Counsel for the US during the Nuremberg proceedings, apparently proposed this expression upon the suggestion of an ‘eminent scholar of international law’ (Minutes of the London Conference Session of 2 August 1945 <http://avalon.law.yale.edu/imt/jack59.asp> [accessed 14 January 2022])—possibly a reference to H Lauterpacht.
6 In the IMT Charter, crimes against humanity were defined as ‘murder, extermination, enslavement, deportation, and other inhumane acts committed against any civilian population, before or during the war, or persecutions on political, racial or religious grounds in execution of or in connection with any crime within the jurisdiction of the Tribunal, whether or not in violation of the domestic law of the country where perpetrated’ (Art. 6 (c) IMT Charter).
7 The close link between this type of crime and the other crimes within the jurisdiction of the IMT effectively meant that crimes against humanity would be punished only if committed during the war or its preparation and if they directly affected the interests of other States.
8 Several defendants at Nuremberg asserted defences based on the principle of legality with respect to this provision and the discussion on whether Art. 6 (c) IMT Charter constituted new law or the crystallization of emerging custom persisting to date (see also Nulla poena nullum crimen sine lege). The IMT, however, did not address the issue directly. Indeed, it often conflated the notions of war crimes and crimes against humanity when entering convictions. Ultimately, the IMT convicted only two defendants—Julius Streicher and Baldur von Schirach—of crimes against humanity independently of war crimes. It is hard to dispel the impression that at least some participants in the Nuremberg trials considered crimes against humanity punishable only because the conduct was, at the same time, also a war crime. Nonetheless, to the extent that crimes against humanity included crimes committed by Germans against other Germans within the boundaries of Germany, they represented a radical innovation in international law.
9 While the Charter of the International Military Tribunal for the Far East (International Military Tribunal for the Far East (IMTFE)) follows the wording of the IMT Charter, the Allies abandoned the link between armed conflict and crimes against humanity when they enacted Control Council Law No 10 in December 1945 for the trial of other war criminals in Europe (see Art. II (1) (c) Control Council Law No 10). In one of these cases, the US Military Tribunal justified the resulting encroachment on State sovereignty by arguing that the accused were being tried ‘because they are accused of having offended against society itself, and society, as represented by international law, has summoned them for explanation’ (United States v Ohlendorf et al [Einsatzgruppen Case] Case No 9  Trials of War Criminals before the Nuremberg Military Tribunals under Control Council Law No 10 vol IV 462). Some domestic jurisdictions, including the Netherlands, France, Poland, and Israel, also proceeded to try individuals for crimes against humanity committed during World War II in light of the IMT judgment and of other decisions by Allied military tribunals. Other countries, such as Italy, have never issued decisions specifically on crimes against humanity, but have recognized in obiter dicta (Obiter Dictum) that certain conduct qualifying as war crimes might also be termed crimes against humanity (see Priebke Case [Judgment] Military Tribunal of Rome [22 July 1997] (1998) 38 Cassazione penale 689). It should be mentioned that genocide, while at this time considered a crime against humanity, gradually came to be considered a separate offence, requiring proof of the intent to destroy a group in whole or in part. Nonetheless, it is often remarked that war crimes, genocide, and crimes against humanity are interdependent notions (see eg Attorney General of the Government of Israel v Eichmann Israel Supreme Court [29 May 1962]  36 ILR 277; Eichmann Case).
10 Further, in 1946, the United Nations General Assembly (‘UNGA’; United Nations, General Assembly) first recommended the extradition and trial of persons accused of crimes mentioned in the IMT Charter (UNGA Res 3 (I) [13 February 1946] GAOR 1st Session Part I Resolutions 9) and then ‘affirmed’ the principles of the IMT Charter and judgment (UNGA Res 95 (I) [11 December 1946] GAOR 1st Session Part II Resolutions 188 [‘Nuremberg Principles’]). In 1950, the International Law Commission (ILC) adopted a report on the principles of international law recognized by the IMT with commentaries (UN ILC Special Rapporteur J Spiropoulos ‘Report on the Formulation of Nürnberg Principles’ [12 April 1950] UN Doc A/CN.4/22).
11 As discussed above, the very concept of crimes against humanity was introduced by the victorious powers of World War II out of concern for civilians rather than for combatants, who were generally covered by the existing laws and customs of war (Civilian Population in Armed Conflict). Therefore, although originally considered necessary to ground the jurisdiction of the IMT in the prevailing circumstances in 1945, the requirement of a nexus with an armed conflict was thereafter gradually abandoned. As early as 9 December 1948, the UNGA adopted the Convention on the Prevention and Punishment of the Crime of Genocide (‘Genocide Convention’), which affirmed that genocide could be committed ‘in time of peace or in time of war’ (Art. 1 Genocide Convention). Entering into force on 11 November 1970, the UN Convention on the Non-Applicability of Statutory Limitations to War Crimes and Crimes Against Humanity (‘Statutory Limitations Convention’) also explicitly mentions crimes against humanity committed ‘in time of peace’ (Art. 1 (b) Statutory Limitations Convention). Despite its somewhat limited applicability, with only 56 States being parties as of 2021, the Statutory Limitations Convention has played an important role in refining the notion of crimes against humanity (Statutory Limitation). In 2006, the European Court of Human Rights (ECtHR) ruled that a claim by two individuals convicted for crimes against humanity committed in 1949 was inadmissible. In the ECtHR’s view, even though this category of crimes was not listed in the Soviet Criminal Code applicable at the time, it was enshrined in the Nuremberg Principles (Kolk and Kislyiy v Estonia [Decision] [17 January 2006] App 23052/04 and 24018/04). This decision rests on the assumption that the Nuremberg Principles had universal validity and applied even when no nexus with an armed conflict could be shown, at least as long as the crime was part of a widespread and systematic attack (policy requirement; see Korbely v Hungary [ECtHR] App 9174/02, in particular paras 84–95 [19 September 2008], finding that the violation of Common Art. 3 of the Geneva Conventions (Geneva Conventions I–IV ) may in principle amount to a crime against humanity, although other elements were not satisfied in the specific case). Other developments also confirm the abandonment of the requirement of an armed conflict (see paras 13–21 below). Thus, the emergence of crimes against humanity is closely associated with one of the most important international law developments of the last 60 years: the gradual expansion of international human rights law. The willingness of States to ensure protection of fundamental human rights at the international level has led to repeated declarations, covenants and conventions on human rights. UN resolutions have even condemned racial discrimination and apartheid as crimes against humanity (Racial and Religious Discrimination).
12 The first attempt to agree on a code of offences against the peace and security of mankind was abandoned in 1954. The ILC only took up the matter again in 1983 and adopted a Draft Statute for an International Criminal Court (ICC) in 1994, while a final text of the Draft Code of Crimes against the Peace and Security of Mankind (‘ILC Draft Code of Crimes’) was adopted in 1996.
D. The ad hoc Tribunals for the Former Yugoslavia and Rwanda
13 In the meantime, however, the UN Security Council (‘UNSC’; United Nations, Security Council) had established the International Criminal Tribunal for the former Yugoslavia (ICTY) in 1993 and the International Criminal Tribunal for Rwanda (ICTR) in 1994 to deal with serious crimes of international concern committed during the conflicts in the former Yugoslavia and Rwanda (see also Yugoslavia, Dissolution of). Article 5 ICTY Statute and Art. 3 ICTR Statute provided for the prosecution of, inter alia, the following acts as crimes against humanity: murder, extermination, enslavement, deportation, imprisonment, torture, rape, and persecutions on political, racial, and religious grounds, as well as other inhumane acts. However, differences exist between the two ad hoc tribunals, since the ICTY Statute requires that these crimes must have been committed in armed conflict and part of a widespread and systematic attack against any civilian population, while the ICTR Statute specifies that such an attack must have been based on national, political, ethnic, racial, or religious grounds. In particular, the clause that a crime against humanity must be committed in an armed conflict is no longer considered part of the customary international law definition and was omitted from the statutes of later international and ‘hybrid’ tribunals, such as the ICC, the Special Court for Sierra Leone (SCSL), the East Timor Special Panels for Serious Crimes, the Extraordinary Chambers in the Courts of Cambodia (ECCC), and the Kosovo Specialist Chambers (‘KSC’) (<https://www.scp-ks.org/sites/default/files/public/05-l-053_a.pdf> [accessed 14 January 2022]; see also Mixed Criminal Tribunals; Special Panels for Serious Crimes in the Dili District Court: United Nations Transitional Mission in East Timor). This approach is in accordance with the ICTY’s seminal decision on jurisdiction in 1995, in which the Appeals Chamber stated that the requirement of an armed conflict for crimes against humanity is inconsistent with contemporary international custom (Prosecutor v Tadić [Appeals Chamber Decision on the Defence Motion for Interlocutory Appeal on Jurisdiction] IT-94-1-AR72 [2 October 1995] paras 141–42; Tadić Case). Thus, a nexus with the armed conflict is only required by the ICTY Statute as a jurisdictional requirement and is not deemed to be a necessary element under general international law.
14 Instead, the ICTY has held, crimes against humanity must be committed as part of a widespread or systematic attack against the civilian population, that is a large-scale or organized attack the primary object of which is a civilian population. The Kunarac Appeal Judgment and the Blaškić Appeal Judgment by the ICTY have elaborated upon some aspects of the general requirements (‘chapeau elements’) of crimes against humanity. The ICTY has, for example, held that the presence of individual combatants within the targeted population does not change that population’s civilian status (Prosecutor v Blaškić [Appeals Chamber Judgment] IT-95-14-A [29 July 2004] paras 103–16). Additionally, while the attack need not entail the use of armed force to be classified as a crime against humanity, it must arguably involve the commission of multiple acts rising to the same level of gravity as the enumerated inhumane acts. This excludes a series of violations of human rights that are insufficiently egregious from the class of crimes against humanity (ibid paras 135–39). Furthermore, the fact that the perpetrators’ acts must be part of the attack excludes isolated acts from being considered crimes against humanity, even if they were committed at the same time as the attack itself (Prosecutor v Kunarac et al [Appeals Chamber Judgment] IT-96-23 and 96-23/1-A [12 June 2002] para. 100). Moreover, the subjective element (mens rea) requires that perpetrators whose acts are part of the widespread and systematic attack directed against a civilian population have knowledge of that widespread and systematic attack. The perpetrators need not share the purpose of the attack, and may indeed commit a crime against humanity for purely personal reasons (ibid para. 103).
15 The jurisprudence of the ICTY and the ICTR is also a valuable source for precise definitions of the single crimes against humanity due to the number and scope of cases dealt with since their inception. With respect to murder, the ad hoc tribunals have stated that its elements mirror the elements of the war crime of unlawful killing, premeditated or not (Prosecutor v Kupreškić et al [Judgment] IT-95-16-T [14 January 2000] para. 560). Extermination has been defined as killing on a mass scale, to be ascertained in light of all the circumstances under which the incident occurred rather than on the basis of any exact numerical threshold (Prosecutor v Ntakirutimana [Appeals Chamber Judgment] ICTR-96-10-A and 96-17-A [13 December 2004] para. 516). Enslavement signifies the exercise of any or all powers generally attaching to the right of ownership over a person (Prosecutor v Kunarac et al [Appeals Chamber Judgment] paras 116–24; see also Slavery). Deportation or forcible transfer is the forced displacement of persons, beyond a State (or State-like) border or within one country, respectively, even in the absence of the intent to displace the persons on a permanent basis (Prosecutor v Stakić [Appeals Chamber Judgment] IT-97-24-A [22 March 2006] paras 276–308; see also Forced Population Transfer). Imprisonment is arbitrary detention (Detention, Arbitrary) in violation of rules of due process (Prosecutor v Kordić and Čerkez [Appeals Chamber Judgment] IT-95-14/2-A [17 December 2004] para. 116). Torture is defined as the intentional infliction of severe pain or suffering aimed at obtaining information or confessions or at punishing, intimidating, humiliating, coercing, or discriminating (see also Torture, Prohibition of). Torture need not be committed by a public official (Prosecutor v Brđanin [Appeals Chamber Judgment] IT-99-36-A [3 April 2007] paras 244–52). Rape is intentional sexual penetration or other forms of sexual violence of similar gravity. Lack of consent is generally proven by showing the existence of coercive circumstances under which meaningful consent is not possible (Prosecutor v Kunarac et al [Appeals Chamber Judgment] paras 127–33; Gacumbitsi v Prosecutor [Appeals Chamber Judgment] ICTR-2001-64-A [7 July 2006] paras 153–57). The residual category of ‘other inhumane acts’, due to its vagueness, has been questioned in relation to the principle of legality in international law, but there is little doubt that gross and systematic human rights violations of a gravity and character comparable to the crimes listed above fall under the customary international law definition (Prosecutor v Kordić and Čerkez Cases [Appeals Chamber Judgment] para. 117).
16 However, the single most analysed crime against humanity in the jurisprudence of the ICTY remains persecution on political, racial, and religious grounds. Prosecuting authorities have apparently considered this to be the concept that best captures the phenomenon of ethnic cleansing. It has been noted that just as genocide has become the offence often used to refer to the events in Rwanda during 1994, the crime against humanity of persecution has come to typify what happened in the territory of the former Yugoslavia. Persecution’s objective element (actus reus) is constituted by an underlying act which discriminates in fact and must deny a fundamental human right laid down in international law (Prosecutor v Krnojelac [Appeals Chamber Judgment] IT-97-25-A [17 September 2003] para. 185). While not every denial of a right will be serious enough to constitute persecution, it is clear that this ‘underlying act’ itself need not constitute a crime in international law; however, considered in isolation or in conjunction with other acts, it must be of the same gravity as other crimes listed under Art. 5 ICTY Statute or Art. 3 ICTR Statute (see Prosecutor v Kupreškić et al [Judgment] para. 621; Prosecutor v Kvočka et al [Appeals Chamber Judgment] IT-98-30/1-A [28 February 2005] para. 323; Prosecutor v Blaškić [Appeals Chamber Judgment] para. 135). The question of whether a given act, such as harassment or humiliation, amounts to persecution is answered not with reference to its apparent cruelty but with reference to the discrimination the act seeks to inspire. On this basis, the tribunals have recognized conduct such as the denial of freedom of movement (see also Movement, Freedom of, International Protection), the denial of employment (see also Work, Right to, International Protection), the denial of the right to judicial process (see also Fair Trial, Right to, International Protection), and the denial of equal access to public services as constituting persecutory acts (see also Equality of Individuals). Following this line of reasoning, the ICTR Appeals Chamber has further ruled that hate speech targeting a population on one of the prohibited discriminatory grounds violates the right to respect for human dignity of the members of that group and thus constitutes ‘discrimination in fact’ (Human Dignity, International Protection). Hate speech, when it occurs in the context of a massive campaign of other discriminatory acts, may therefore rise to the required level of gravity so as to amount to persecution (Nahimana et al v Prosecutor [Appeals Chamber Judgment] ICTR-99-52-A [28 November 2007] paras 987–88; Nahimana and Others Case).
17 Ultimately, the distinctive feature of persecution is its subjective element (mens rea), ie the intent of the perpetrator to discriminate on one of the grounds mentioned above. While the jurisprudence of the ad hoc tribunals has found that the act must ‘discriminate in fact’, it has also hinted that the perpetrator’s state of mind is essential in this determination (Prosecutor v Krnojelac [Appeals Chamber Judgment] paras 184–85). Thus, for example, persons targeted because of their former membership in a political party or because they are married to persons belonging to the targeted ethnicity may, depending on the circumstances, be considered victims of persecution even if they themselves are not members of that group.
E. ICC Statute, Customary International Law, and the Draft Convention
18 Article 7 Rome Statute of the International Criminal Court (‘ICC Statute’) lists as crimes against humanity, with minor variations, the acts enumerated in the ILC Draft Code of Crimes and in the ICTY and ICTR Statutes. As for all crimes under the jurisdiction of the ICC, crimes against humanity are further elaborated upon in the ‘Elements of Crimes’ (<https://www.icc-cpi.int/Publications/Elements-of-Crimes.pdf> [accessed 14 January 2022]).
19 The ICC Statute, however, defines some aspects of crimes against humanity differently from the statutes of the ad hoc tribunals or customary international law. First, the ICC Statute requires the perpetrator to commit a crime against humanity in pursuit or furtherance of a ‘State or organizational policy to commit’ an attack against a civilian population (Art. 7 (2) (a) ICC Statute). A proper interpretation of this clause within the Statute and in light of customary law appears to be the most relevant distinguishing feature between the ICC Statute and other judicial institutions adjudicating crimes against humanity, and remains a challenge for both the parties and the judges to interpret and apply. Second, the discriminatory grounds listed by the ICC Statute are not limited to political, racial, national, ethnic, or religious grounds, but encompass also cultural, gender, and ‘other grounds that are universally recognized as impermissible under international law’ (Art. 7 (1) (h) ICC Statute). Third, crimes against humanity under the ICC Statute also include conduct such as enforced prostitution, forced pregnancy, enforced sterilization, enforced disappearance of persons, and apartheid (see also Disappearances; Gender-Based Crimes), whereas it is not established that all of these acts amount to crimes against humanity under customary international law. Fourth, for the purposes of the ICC, persecution must be committed in connection with other acts or crimes within the jurisdiction of the ICC. However, because of the paucity of substantive decisions on guilt or innocence related to crimes against humanity from the ICC, it is still difficult to foresee the extent to which these differences will impact on the development of customary international law, if at all (see, in this respect, the statement in the ICC Statute that no provision related to the ICC’s jurisdiction ‘shall be interpreted as limiting or prejudicing in any way existing or developing rules of international law for purposes other than this Statute’ [Art. 10 ICC Statute]).
20 Owing to the lack of a generally agreed definition, terrorism was not explicitly included among the crimes that fall under the jurisdiction of the ICC. However, when the general requirements mentioned above are met, terrorist acts undoubtedly fall within the remit of the category of crimes against humanity and can be prosecuted accordingly.
21 The ILC, at its 66th Session in 2014, decided to include the topic ‘Crimes against Humanity’ in its programme of work. Further to lengthy discussion and the work of the Special Rapporteur, Sean D Murphy, at its 71st Session in 2019, the ILC adopted Draft Articles on the Prevention and Punishment of Crimes Against Humanity, comprising a draft preamble, 15 draft articles, a draft Annex, and relevant commentaries, recommending the elaboration of a convention by the General Assembly or by an international conference of plenipotentiaries on the basis of the draft articles. The approach follows a general agreement in the ILC that the definition of crimes against humanity contained in the Rome Statute should not be modified, the two main differences being the elimination of the (jurisdictional) connection of persecution with genocide or war crimes that exists for the ICC (‘any crime within the jurisdiction of the Court’) and of the clause according to which ‘“gender” refers to the two sexes, male and female, within the context of society’. The Draft Convention then includes several other important provisions, such as on non-refoulement, aut dedere aut iudicare, and obligations for domestic investigation and prosecution, as well as fair treatment against alleged offenders and protection for victims and witnesses. On 18 November 2021, however, the UNGA’s Sixth Committee (United Nations, Sixth Committee) simply took note of the Draft Articles by adopting Draft Resolution A/C.6/76/L.17 without a vote (UN Doc A/C.6/76/L.17).
22 The ad hoc tribunals have authoritatively ruled that the criminalization of conduct amounting to crimes against humanity has reached the status of customary international law. Crimes against humanity are also deemed to amount to ius cogens, non-derogable rules of international law. This would imply, according to several scholars, that perpetrators of crimes against humanity, whatever their status or immunity within their domestic systems, are subject to universal jurisdiction by any State and are protected by no statute of limitation (see also Criminal Jurisdiction of States under International Law; eg in the Priebke case [see para. 9 above]). On the consequences of this rule for amnesties, reference can be made to Simón, Julio Hector y otros s/ privación ilegítima de la libertad (Judgment) (Supreme Court of Argentina Case No 17.768 [14 June 2005], available at <https://www.legal-tools.org/doc/c624f4/> [accessed 14 January 2022]) and Almonacid-Arellano et al v Chile (Judgment) IACtHR Series C No 154 (26 September 2006). The decision of the Inter-American Court of Human Rights (IACtHR) relied on the ICTY definition of murder as a crime against humanity and dealt with the Chilean law on amnesty. Regarding the issue of immunity for former Heads of State charged with torture upon Great Britain’s implementation of the Convention against Torture, the judgment issued by the House of Lords in the Pinochet Cases on 24 March 1999 can be consulted (Regina v Bartle ex parte Pinochet (1999) 38 ILM 581).
23 Additionally, a number of widely ratified conventional instruments enshrine the principle of aut dedere aut iudicare in relation to specific crimes against humanity, such as torture. This expression refers to the alternative obligation of a State holding an alleged perpetrator either to extradite the individual or properly to set in motion the procedure to prosecute the alleged perpetrator within its own jurisdiction.
24 In the past few years, more and more States have established the category of crimes against humanity and have defined triable offences within their domestic legal systems, whether by means of legislation or by deriving their existence from international law. An interesting example in this respect is provided by Bosnia and Herzegovina, which has adopted the international law definition of crimes against humanity into Art. 172 of its Criminal Code of 2003 (Criminal Code of Bosnia and Herzegovina  <http://www.legislationline.org/documents/section/criminal-codes/country/40> [accessed 14 January 2022]). Courts have applied this provision to events in the 1990s on the basis of the fact that international law was sufficient to found jurisdiction over crimes against humanity committed in that country during the conflict (see eg Stanković Case [Judgment] Court of Bosnia and Herzegovina No X-KR-05/70 [14 November 2006] Official Gazette of the Federation of Bosnia and Herzegovina No 37). Courts in other jurisdictions have started applying their own provisions, with reference to relevant international case law (see eg Octavien Ngenzi and Tite Barahirwa Case [Appeal Judgment] French Appeal Criminal Court [6 July 2018] <https://www.legal-tools.org/doc/dff591/> [accessed 14 January 2022]).
25 The current criminalization of conduct defined as crimes against humanity is essentially a product of the work of the ad hoc tribunals since the mid-1990s. Before this period, despite some good faith efforts through multilateral negotiations and the spearheading effect of UN-backed definitions, the notion of crimes against humanity was vague and ambiguous. However, notwithstanding the huge developments in the past 30 years, crimes against humanity are not yet as firmly established in international criminal law as other more longstanding concepts, such as war crimes. Moreover, the ILC and the Sixth Committee have only recently started playing a role in entrenching the notion of crimes against humanity and ensuring a fair and effective prosecution for this type of allegation—their efforts have yet to bring about concrete results. Ensuring adherence to the principle of legality when adjudicating allegations of responsibility for crimes against humanity remains a live concern. This is particularly the case with respect to persecution, as the open-ended definition of the actus reus of persecution would seem to facilitate the incorporation of a growing range of fundamental human rights violations into the class of crimes against humanity. Another area of possible concern relates to the interaction between war crimes and crimes against humanity. Although it is clear that crimes against humanity committed during armed conflict may be charged cumulatively with the corresponding war crimes (as the ICTY and the ICTR generally allow), the overlap between these categories remains insufficiently explored.
Charter of the International Military Tribunal for the Far East (proclaimed on 19 January 1946) in RJ Pritchard (ed) The Tokyo Major War Crimes Trial, The Records of the International Military Tribunal for the Far East with an Authoritative Commentary and Comprehensive Guide vol 2 The Proclamation of the Tribunal, The Charters of the Tribunal, Appointments of the Members, Rules of Procedure, The Indictment, The Lodging of the Indictment, The Arraignment and The Case for the Prosecution (The Edwin Mellen Press New York 1998).
Charter of the Nuremberg International Military Tribunal (proclaimed on 8 August 1945) in United Nations The Charter and Judgment of the Nürnberg Tribunal: History and Analysis (3 March 1949) UN Doc A/CN.4/5 (United Nations Publications New York 1949).
Control Council Law No 10 ‘Punishment of Persons Guilty of War Crimes, Crimes Against Peace and Against Humanity’ (20 December 1945) 3 Official Gazette of the Control Council for Germany 50–55 (1946).
Convention on the Non-Applicability of Statutory Limitations to War Crimes and Crimes against Humanity (adopted 26 November 1968, entered into force 11 November 1970) 754 UNTS 73.
Convention on the Prevention and Punishment of the Crime of Genocide (adopted 9 December 1948, entered into force 12 January 1951) 78 UNTS 277.
Hague Convention with Respect to the Laws and Customs of War on Land and its Annex: Regulations concerning the Laws and Customs of War on Land (signed 29 July 1899, entered into force 4 September 1900) (1898–99) 187 CTS 429 (Hague Convention II).
Rome Statute of the International Criminal Court (adopted 17 July 1998, entered into force 1 July 2002) 2187 UNTS 90 (Rome Statute).
UN ILC ‘Draft Articles on Prevention and Punishment of Crimes Against Humanity’ in ‘Report of the International Law Commission: Seventy-first Session’ (29 April–7 June and 8 July–9 August 2019) UN Doc A/74/10, 11.
UN ILC ‘Draft Code of Crimes against the Peace and Security of Mankind’ (1996) GAOR 51st Session Supp 10, 9.
UNSC ‘Statute of the International Criminal Tribunal for the Former Yugoslavia’ UNSC Res 827 (1993) (25 May 1993) SCOR 48th Year 29.
UNSC ‘Statute of the International Tribunal for Rwanda’ UNSC Res 955 (1994) (8 November 1994) SCOR 49th Year 13.