In 1948, the United Nations General Assembly voted unanimously to create the UN Convention on the Prevention and Punishment of the Crime of Genocide. Recognizing that “at all periods of history genocide has inflicted great losses on humanity” and that international cooperation was needed “to liberate mankind from this odious scourge,” the Convention criminalized certain acts committed with the intent to destroy ethnic, national, racial, or religious groups.

But how has the definition of genocide—crafted through diplomatic negotiation—become meaningful against real threats to civilian groups?

Only a handful of individuals were held accountable for genocide in the decades following 1951, when the Convention came into effect. Few and far between, these trials were held by national courts, which often used national adaptations of the international law of genocide. For example, Adolf Eichmann was prosecuted under an Israeli law very similar to “genocide,” but covering crimes against the Jewish people.

In 1993, in response to massive atrocities in Croatia and Bosnia-Herzegovina, the United Nations Security Council created the International Criminal Tribunal for the Former Yugoslavia (ICTY). It was the first international criminal tribunal since Nuremberg and the first ever mandated to prosecute the crime of genocide. A year later, in response to devastating violence in Rwanda, the Security Council established the International Criminal Tribunal for Rwanda (ICTR). Nearing the completion of their mandates, both of tribunals have contributed detail, nuance, and precedent to the application of the law of genocide.

In 1998, the Rome Statute of the International Criminal Court (ICC) established the first permanent international criminal court. The Rome Statute’s drafting process and the ICC’s ongoing case against the president of Sudan have added further clarifications to the international law of genocide. In 2007, the International Court of Justice (ICJ), which hears cases between states, issued a landmark decision addressing state responsibility to prevent and punish genocide in the case of Bosnia and Herzegovina v. Serbia and Montenegro.

Law grows through the setting of precedents. Understanding the intricacies of the definition of genocide is just the first step to understanding the law, which evolves through legal judgments in cases before the tribunals and courts.

Outlined below, you will find the main definitional elements of the crime of genocide and explanations on how significant aspects of the law have developed through recent cases.

Article I of the UN Convention on the Prevention and Punishment of the Crime of Genocide:

“The Contracting Parties confirm that genocide, whether committed in time of peace or in time of war, is a crime under international law which they undertake to prevent and punish.”

Significantly, Article 1 of the Convention establishes the crime of genocide in times of war or peace. In 1948, this definition differed considerably from that of crimes against humanity, which only concerned violations against civilians during war—a limitation on the definition that no longer applies.

A signature to the Convention confers upon the state certain duties: to enact national legislation that punishes genocide committed in its territory and that does not allow for the legal defense of acting in an official capacity; to take measures to reasonably ascertain the location of an accused individual within the state’s own borders and arrest him; to cooperate with extradition requests; and to send disputes between nations to the ICJ, individual criminal cases to a national or international tribunal, or to refer a case to the “competent organs of the United Nations.”

The 2007 ICJ decision in the case of Bosnia and Herzegovina v. Serbia and Montenegro—which found that Serbia violated its responsibility to prevent and punish genocide at Srebrenica, Bosnia-Herzegovina—clarified that a state’s prevention and punishment obligations extend beyond its own borders. The decision asserted that states are obliged to take “all means reasonably available to them, so as to prevent genocide so far as possible.” This obligation exists regardless of whether the state’s efforts to influence the perpetrators changes the outcome.

Article II

“In the present Convention, genocide means any of the following acts committed with the intent to destroy...”

The definition of genocide requires that the perpetrator have a specific state of mind: the “intent to destroy” a group. The intent to destroy is distinct from a perpetrator’s particular motive for the crime, like counter-insurgency. In the absence of explicit evidence, intent can be inferred from facts and circumstances that take into account the general context of the crime, such as: preparation of other culpable acts systematically and exclusively directed against the same group; scale of atrocities committed; weapons employed; the extent of bodily injury; and/or the repetition of destructive and discriminatory acts.

While legal decisions have not generally required proof of agreements or plans in order to convict on genocide, the criminal cases at the ICTY and ICTR have set a high standard for assessing the perpetrator’s state of mind: genocidal intent must be the only reasonable inference based on the facts and circumstances.

Important decisions that concern intent to destroy include the ICTY cases against Goran Jelisic, Mitar Vasiljevic, and Radoslav Brdanin, and the ICTR case against Sylvestre Gacumbitsi.

“...in whole or in part...”

Legal decisions have not established a numeric threshold that a perpetrator must reach in order to possess the intent to commit genocide. They have, however, elaborated on the meaning of “in whole or in part” as a substantial part of the group relative to the total population of the group. Providing guidance on how to evaluate what constitutes “a substantial part,” the courts have issued decisions indicating that the number of individuals targeted should be evaluated in relation to the overall size of the entire group, their prominence within the group, and whether or not the part of the group is emblematic of the overall group or essential to its survival.

For example, the decision by the ICTY Appeals Chamber in the Krstic case reasoned that the population of Muslim men targeted in Srebrenica was important because of its “strategic importance to the Bosnian Serb leadership and because of its prominence in the eyes of the Bosnian Muslims and the international community, its fate was emblematic of that of all Bosnian Muslims.”

Important decisions that concern the group, in whole or in part, include the ICTY cases against Radislav Krstic and Duško Sikirica et al.

"...a national, ethnical, racial or religious group.”

The Convention designates certain groups that accorded with the common understanding of “national minorities” at the time of the document’s drafting. In the first genocide conviction ever, the ICTR determined in the case against Jean-Paul Akayesu that all “stable and permanent groups” were protected by the Convention. In a later ruling, however, the ICTY argued that a persecuted group is often defined by the perpetrators based on perceived characteristics. The ICTY also asserted that a group cannot be defined negatively; the victims cannot be “non-Serbs,” for instance.

Important decisions that concern the designation of the group include the ICTR case against Jean-Paul Akayesu and the ICTY cases against Radoslav Brdanin and Milomir Stakic, among others.

Article II: Acts of Genocide

The following acts can be considered genocide when (and only when) they are committed with the intent to destroy a group protected by the Convention:

  • killing, causing serious bodily or mental harm;
  • deliberately inflicting on the group conditions calculated to bring about its physical destruction in whole or in part;
  • imposing measures intended to prevent births within the group;
  • and forcibly transferring children of the group to another group.

Some of these acts are more clearly defined than others. For instance, the tribunals have elaborated on the act of “causing serious bodily or mental harm to members of the group.” In the Akayesu case, the ICTR decided that the harm need not be permanent or irremediable and can include torture, be it “bodily or mental, inhumane or degrading treatment, persecution.” The judgment in this case allowed rape to be considered an act of genocide when committed with the intent to destroy a protected group. The tribunals further confirmed that the harm also includes sexual violence that falls short of killing.

Important decisions that concern the act of causing serious bodily or mental harm include the ICTR cases against Jean-Paul Akayesu and Laurent Semanza.


Although cases are still pending, the decisions passed down by the two international criminal tribunals and the ICJ have clarified the definition of the crime of genocide. As these legal institutions hear more cases, our understanding of the crime will develop. One of the key questions for future legal forums is whether the Convention can be used effectively not only to punish acts that have already taken place, but also to prevent crimes and protect groups.