Drafted in the shadow of the Holocaust, the Convention on the Prevention and Punishment of the Crime of Genocide (Genocide Convention) defined the international crime of genocide for the first time. Central to the Genocide Convention, and to the crime that it defined, is a unique focus on groups. Raphaël Lemkin, the inventor of the term “genocide,” understood the crime as an effort aimed at “the destruction of essential foundations of the life of national groups, with the aim of annihilating the groups themselves.” Article 2 of the Genocide Convention reflects Lemkin's desire to protect groups as social units by providing that only actions committed with the intent to destroy certain groups as such constitute genocide. Distinct from mass killing, which targets individuals, genocide targets the group to which those individuals belong...