‘The fact of genocide is as old as humanity’, wrote Jean-Paul Sartre.Footnote ¹ The law, however, is considerably younger. This dialectic of the ancient fact yet the modern law of genocide follows from the observation that, historically, genocide has gone unpunished. Hitler’s famous comment, ‘who remembers the Armenians?’, is often cited in this regard.Footnote ² Yet the Nazis were only among the most recent to rely confidently on the reasonable presumption that an international culture of impunity would effectively shelter the most heinous perpetrators of crimes against humanity.

The explanation for this is straightforward: genocide was generally, although perhaps not exclusively, committed under the direction or, at the very least, with the benign complicity of the State where it took place. Usually, the crime was executed as a quite overt facet of State policy, particularly within the context of war or colonial conquest. Obviously, therefore, domestic prosecution was virtually unthinkable, even where the perpetrators did not in a technical sense benefit from some manner of legal immunity. Only in rare cases where the genocidal regime collapsed in its criminal frenzy, as in Germany or Rwanda, could accountability be considered.

The inertia of the legal systems where the crimes actually occurred did little to inspire other jurisdictions to intervene, although they did so with respect to certain other ‘international crimes’ such as piracy and the trafficking in persons, where the offenders were by and large individual villains rather than governments and where the crimes often took place outside the territorial jurisdiction of any State. Refusal to exercise universal jurisdiction over these offences against humanitarian principles was defended in the name of respect for State sovereignty. But it had a more sinister aspect, for this complacency was to some extent a form of quid pro quo by which States agreed, in effect, to mind their own business. What went on within the borders of a sovereign State was a matter that concerned nobody but the State itself.

This began to change at about the end of the First World War and is, indeed, very much the story of the development of human rights law, an ensemble of legal norms focused principally on protecting the individual against crimes committed by the State. It imposes obligations upon States and ensures rights to individuals. Because the obligations are contracted on an international level, they pierce the hitherto impenetrable wall of State sovereignty. There is also a second dimension to international human rights law, this one imposing obligations on the individual who, conceivably, can also violate the fundamental rights of his or her fellow citizens. Where these obligations are breached, individuals may be punished for such international crimes as a matter of international law, even if their own State, or the State where the crime was committed, refuses to do so. Almost inevitably, the criminal conduct of individuals blazes a trail leading to the highest levels of government, with the result that this aspect of human rights law has been difficult to promote. While increasingly willing to subscribe to human rights standards, States are terrified by the prospect of prosecution of their own leaders and military personnel, either by international courts or by the courts of other countries, for breaches of these very norms. To the extent that such prosecution is even contemplated, States insist upon the strictest of conditions and the narrowest of definitions of the subject matter of the crimes themselves. The law of genocide is a paradigm for these developments in international human rights law. As the prohibition of the ultimate threat to the existence of ethnic groups, it is right at the core of the values protected by human rights instruments and customary norms.

The law is posited from a criminal justice perspective, aimed at individuals yet focused on their role as agents of the State. The crime is defined narrowly, a consequence of the extraordinary obligations that States are expected to assume in its prevention and punishment. The centrepiece in any discussion of the law of genocide is the Convention on the Prevention and Punishment of the Crime of Genocide, adopted by the United Nations General Assembly on 9 December 1948.Footnote ³ The Convention came into force in January 1951, three months after the deposit of the twentieth instrument of ratification or accession.

In its Advisory Opinion on reservations to the Genocide Convention, the International Court of Justice wrote that:

This important statement is often cited as the judicial recognition of the prohibition of genocide as a customary legal norm, although the Court does not refer to it expressly in this way.

The Statute of the International Court of Justice recognizes two non-conventional sources of international law: international custom and general principles.Footnote ⁵ International custom is established by ‘evidence of a general practice accepted as law’, while general principles are those ‘recognized by civilized nations’. Reference by the Court to such notions as ‘moral law’ as well as the quite clear allusion to ‘civilized nations’ suggest that it may be more appropriate to refer to the prohibition of genocide as a norm derived from general principles of law rather than a component of customary international law. On the other hand, the universal acceptance by the international community of the norms set out in the Convention since its adoption in 1948 means that what originated in ‘general principles’ ought now to be considered a part of customary law.Footnote ⁶ In 2006, the International Court of Justice held that the prohibition of genocide was ‘assuredly’ a peremptory norm (jus cogens) of public international law, the first time it has ever made such a declaration about any legal rule.Footnote ⁷ A year later, it said that the affirmation in article I of the Convention that genocide is a crime under international law means it sets out ‘the existing requirements of customary international law, a matter emphasized by the Court in 1951’.Footnote ⁸

Besides the Genocide Convention itself, there are other important positive sources of the law of genocide. The Convention was preceded, in 1946, by a resolution of the General Assembly of the United Nations recognizing genocide as an international crime, putting individuals on notice that they would be subject to prosecution and could not invoke their own domestic laws in defence to a charge.Footnote ⁹ Since 1948, elements of the Convention, and specifically its definition of the crime of genocide, have been incorporated in the statutes of the two ad hoc tribunals created by the Security Council to judge those accused of genocide and other crimes in the former Yugoslavia and Rwanda.Footnote ¹⁰ Affirming its enduring authority, the Convention definition was included without any significant modification in the Rome Statute of the International Criminal Court, which was adopted on 17 July 1998 and entered into force on 1 July 2002.Footnote ¹¹ A subsidiary document to the Rome Statute, the Elements of Crimes, provides additional contextual components for the interpretation of the definition. There have been frequent references to genocide within the resolutions, declarations and statements of United Nations organs, including particularly the work of expert bodies, special rapporteurs and fact-finding commissions.Footnote ¹² In 2004, the Secretary-General of the United Nations established a Special Adviser on the Prevention of Genocide, a senior position within the Secretariat with responsibility for warning the institution of threatened catastrophes. In the World Summit Outcome resolution of 2005, the General Assembly endorsed the Special Adviser.Footnote ¹³

A large number of States have enacted legislation concerning the prosecution and repression of genocide, most by amending their penal or criminal codes in order to add a distinct offence. Usually they have borrowed the Convention definition, as set out in articles II and III, but several have contributed their own innovations. Sometimes these changes to the text of articles II and III have been aimed at clarifying the scope of the definition, for both internal and international purposes. For example, the United States of America’s legislation specifies that destruction ‘in whole or in part’ of a group, as stated in the Convention, must actually represent destruction ‘in whole or in substantial part’.Footnote ¹⁴

Others have attempted to enlarge the definition, by appending new entities to the groups already protected by the Convention. Examples include political, economic and social groups. Going even further, France’s Code pénal defines genocide as the destruction of any group whose identification is based on arbitrary criteria.Footnote ¹⁵ The Canadian implementing legislation for the Rome Statute states that ‘“genocide” means an act or omission committed with intent to destroy, in whole or in part, an identifiable group of persons, as such, that, at the time and in the place of its commission, constitutes genocide according to customary international law’, adding that the definition in the Rome Statute, which is identical to that of the Convention, is deemed a crime according to customary international law. The legislation adds, in anticipation: ‘This does not limit or prejudice in any way the application of existing or developing rules of international law.’Footnote ¹⁶

The variations in national practice contribute to an understanding of the meaning of the Convention but also, and perhaps more importantly, of the ambit of the customary legal definition of the crime of genocide. Yet rather than imply some larger approach to genocide than that of the Convention, the vast majority of domestic texts concerning genocide repeat the Convention definition and tend to confirm its authoritative status.

The Convention on the Prevention and Punishment of the Crime of Genocide is, of course, an international treaty embraced by the realm of public international law. Within this general field, it draws on elements of international criminal law, international humanitarian law and international human rights law. By defining an international crime, and spelling out obligations upon States Parties in terms of prosecution and extradition, the Convention falls under the rubric of international criminal law.Footnote ¹⁷ Its claim to status as an international humanitarian law treaty is supported by the inclusion of the crime within the subject matter jurisdiction of the two ad hoc tribunals charged with prosecuting violations of humanitarian law.Footnote ¹⁸ Genocide is routinely subsumed – erroneously – within the broad concept of ‘war crimes’. Nevertheless, the scope of international humanitarian law is confined to international and non-international armed conflict, and the Convention clearly specifies that the crime of genocide can occur both in war and in peacetime. Consequently, it may more properly be deemed an international human rights law instrument. Indeed, René Cassin once called the Genocide Convention a specific application of the Universal Declaration of Human Rights.Footnote ¹⁹ Alain Pellet described the Convention as ‘a quintessential human rights treaty’.Footnote ²⁰ For Benjamin Whitaker, genocide was ‘the ultimate human rights problem’.Footnote ²¹ The Convention appears under the heading ‘Human Rights’ on the list of ‘Multilateral Treaties Deposited with the Secretary-General’ of the United Nations Treaty Collection website.

The prohibition of genocide is closely related to the right to life, one of the fundamental human rights defined in international declarations and conventions. These instruments concern themselves with the individual’s right to life, whereas the Genocide Convention is associated with the right to life of human groups, sometimes spoken of as the right to existence. General Assembly Resolution 96 (I), adopted in December 1946, declares that ‘genocide is a denial of the right of existence of entire human groups, as homicide is the denial of the right to live of individual human beings’. States ensure the protection of the right to life of individuals within their jurisdiction by such measures as the prohibition of murder in criminal law. The repression of genocide proceeds somewhat differently, the crime being directed against the entire international community rather than the individual. As noted by Mordechai Kremnitzer, ‘it is a frontal attack on the value of human life as an abstract protected value in a manner different from the crime of murder’.Footnote ²²

In the half-century following its adoption, there was little attention, scholarly or judicial, to the legal aspects of the Genocide Convention. Most academic research on the Genocide Convention had been undertaken by historians and philosophers. They frequently ventured onto judicial terrain, not so much to interpret the instrument and to wrestle with the legal intricacies of the definition as to express frustration with its limitations. Even legal scholars tended to focus on what were widely perceived as the shortcomings of the Convention. The Convention definition of genocide seemed too restrictive, too narrow. It had failed to cover, in a clear and unambiguous manner, many of the major human rights violations and mass killings perpetrated by dictators and their accomplices. Jurists often looked to the Genocide Convention in the hope it might apply and either proposed exaggerated and unrealistic interpretations of its terms or else called for its amendment so as to make it more readily applicable. The principal deficiency, many argued, was that it applied only to ‘national, racial, ethnical and religious groups’.

The third quarter-century since adoption of the Convention has brought unprecedented attention to the international legal issues it raises. Whereas only two contentious cases based upon the Convention were filed at the International Court of Justice prior to 1998, since then there have been fifteen applications as well as two counter-claims and two major judgments. Numerous decisions have been issued on the subject by international and internationalised tribunals, including the International Criminal Court, the International Criminal Tribunal for Rwanda, the International Criminal Tribunal for the former Yugoslavia, the International Residual Mechanism for Courts and Tribunals, the European Court of Human Rights and the Extraordinary Chambers of the Courts of Cambodia. National legislatures and political personalities regularly invoke the term ‘genocide’ in order to characterize a range of atrocity crimes, both present and historic.Footnote ²³ Many perpetrators of the crime are now in prison, convicted of genocide by the international criminal tribunals for Rwanda and the former Yugoslavia. Thousands have been prosecuted at the national level, notably in Rwanda itself.

This intense legal activity relating to the crime of genocide is part of the much broader phenomenon of the development of contemporary international criminal justice. It has been characterized by a huge enlargement of the subject matter. Until the 1990s, the prevailing view failed to recognize ‘war crimes’ in non-international armed conflict. Furthermore, the Nuremberg precedent appeared to exclude ‘crimes against humanity’ committed in peacetime. The Rome Statute of the International Criminal Court, adopted in 1998, confirmed a radical expansion of the scope of international criminal justice by modifications to both of these categories. Paradoxically, the crime of genocide has resisted any expansion. There were only a few perfunctory attempts to amend it during the drafting of the Rome Statute and there have been no serious proposals of amendment since then. Moreover, judges of the international tribunals have generally resisted encouragement to extend the application of the crime through judicial activism. This may be explained by the legal development of war crimes and crimes against humanity. In expanding war crimes and crimes against humanity to fill gaping impunity gaps, pressure to do the same with genocide was reduced. The perceived shortcomings of the narrow definition of genocide in the 1948 Convention were very thoroughly addressed by amendments to the other international crimes. Yet the obsession with genocide has remained. It is a label that many consider to be the only adequate way to describe severe acts of persecution, of massacre and of atrocity. Raphael Lemkin, who proposed the term ‘genocide’ and who devoted his life to the campaign for its recognition, spoke of it as the ‘crime of crimes’.Footnote ²⁴

As a practical matter, the atrocities that do not fit neatly within the parameters of genocide, as defined in the Convention, invariably fall under the broader concept of crimes against humanity. At the international criminal tribunals, where subject-matter jurisdiction extends to genocide, crimes against humanity and war crimes, acquittal on a genocide count is usually accompanied by conviction for one of the lesser and included charges. But this is not possible in litigation at the International Court of Justice premised on the Convention itself, because a failure to prove genocide has meant dismissal of the application altogether.

Sometimes judges have insisted on conceptual distinctions between the two categories on the ground that genocide is aimed at protection of national, ethnic, racial and religious groups whereas crimes against humanity applies to ‘any civilian population’.Footnote ²⁵ The question has arisen in the context of multiple charges, and the permissibility of convicting where two offences contain essentially the same elements. According to the Appeals Chamber of the International Criminal Tribunal for Rwanda, it is acceptable to register a conviction for both genocide and the crime against humanity of extermination with regard to the same factual elements. Following the test developed by the tribunals, multiple convictions are allowed where there are materially distinct elements of each infraction. Whereas genocide requires proof of an intent to destroy, in whole or in part, a national, ethnical, racial or religious group, ‘this is not required by extermination as a crime against humanity. Extermination as a crime against humanity requires proof that the crime was committed as a part of a widespread or systematic attack against a civilian population, which proof is not required in the case of genocide’.Footnote ²⁶

But there is much compelling support from other authorities for the view that the two categories, genocide and crimes against humanity, are intimately related.Footnote ²⁷ The judges of the tribunals probably missed a good opportunity to rationalize the relationship between genocide and crimes against humanity, a mission the International Criminal Tribunal for the former Yugoslavia accomplished so well with respect to the disparate forms of war crimes recognized by treaty and custom, which it linked within an ‘umbrella’ category of ‘serious violations of international humanitarian law’.Footnote ²⁸ The same might have been done by placing genocide under the umbrella of crimes against humanity.

Since 1948, the law concerning crimes against humanity has evolved substantially. That crimes against humanity may be committed in time of peace as well as war has been recognized in the case law of the ad hoc international tribunalsFootnote ²⁹ and codified in the Rome Statute.Footnote ³⁰ Arguably, the obligations upon States found in the Genocide Convention now apply mutatis mutandis, on a customary basis, in the case of crimes against humanity. Therefore, the alleged gap between crimes against humanity and genocide has narrowed considerably. Speaking of the relative gravity of crimes against humanity, the International Commission of Inquiry on Darfur said ‘it is indisputable that genocide bears a special stigma, for it is aimed at the physical obliteration of human groups. However, one should not be blind to the fact that some categories of crimes against humanity may be similarly heinous and carry an equally grave stigma.’Footnote ³¹

Certainly the practical consequences in a legal sense of the distinction between genocide and crimes against humanity are now less important. Some have argued that we should eliminate the different categories altogether, in favour of an overarching concept of ‘atrocity crime’.Footnote ³² Perhaps reflecting a similar line of thought, in 2006 the Secretary-General proposed renaming the Special Adviser on the Prevention of Genocide, who had only been established two years earlier, as the Special Adviser on the Prevention of Genocide and Mass Atrocity, although he later retreated from this. But the interest in defining a separate offence of genocide persists. In the public debate, suggesting that atrocities are better described as crimes against humanity rather than genocide, as President Jimmy Carter did with reference to Darfur in October 2007, is condemned for trivialization of a humanitarian crisis. Carter was treated unfairly by his critics, who demagogically seized upon his insistence on accurate terminology. He had roundly denounced the ethnic cleansing in Darfur as a crime against humanity and hardly deserved the charges that he was pandering to the Sudanese regime. International lawyers seem sometimes to insist in vain that the distinction between genocide and crimes against humanity is of little or no importance. The argument is not about the state of the law: it is one of symbolism and semantics. If the result of the terminological quarrel is to insist upon the supreme heinousness of ‘racial hatred’, for want of a better term, and to reiterate society’s condemnation of the mass killings of Jews, Tutsi and Armenians, to cite the primary historical examples of the past century, the distinction retains and deserves all of its significance. From this perspective, genocide stands to crimes against humanity as premeditated murder stands to intentional homicide. Genocide deserves its title as the ‘crime of crimes’.

This study follows, in a general sense, the structure of the Convention itself, after an initial presentation of the origins of the norm. An inaugural chapter, with a historical focus, addresses the development of international legal efforts to prosecute genocide, up to and including the Nuremberg trial. Chapters 2 and 3 survey the process of drafting the Convention, as well as subsequent normative activity within United Nations bodies such as the Security Council and the International Law Commission. Chapters 4 to 6 examine the definition of genocide set out in article II, reviewing the groups protected by the Convention, the mens rea or mental element of the offence, the actus reus or physical element of the offence and the punishable acts. Chapter 7 considers the issue of cultural genocide and other acts excluded from the scope of the Convention. Chapter 8 examines the ‘other acts’ enumerated in article III of the Convention. Admissible defences to the crime of genocide are considered in Chapter 9. Domestic and international prosecution of genocide, matters raised by articles V, VI and VII of the Convention, are examined in Chapters 10 and 11. Chapter 12 deals with State responsibility for genocide, an issue addressed indirectly by several provisions of the Convention, including article IX. Chapter 13 is devoted to the prevention of genocide, a question of vital importance but one considered only incompletely in the Convention, principally by articles I and VIII. The activities of international organizations, especially the organs of the United Nations, are assessed in Chapter 14. A variety of treaty law matters addressed in articles X to XIX of the Convention are examined in Chapter 15.

The earlier editions of this study contained extensive citations from the travaux préparatoires of the Genocide Convention. Most of these have been removed in order to reduce the length of this book. At the time, these materials were very difficult to access, and providing the texts verbatim was meant as a service to the reader. As a general rule, the documents could only be found in large research libraries and even then with some difficulty. Since then, the United Nations documents have become generally available at digitallibrary.un.org. The relevant materials have also been compiled in a two-volume collection: Hirad Abtahi and Philippa Webb, eds., The Genocide Convention: The travaux préparatoires, The Hague: Brill, 2008.

The law is up to date as of 2 February 2024.