Genocide and ethnic cleansing are among the most deadly human-made catastrophes. Together with other forms of government violence, such as war crimes and crimes against humanity, the death toll they caused during the 20th century alone approximates 200 million. This is an estimated ten times higher than the number of deaths resulting from all violence committed in civil society during the same period. Yet the definition of genocide, its perception as a social problem, and the designation of responsible actors as criminals are all relatively recent. Globalization, international organizations, nongovernmental organizations, and cultural shifts are interrelated contributors to this process of redefinition.
While genocide and ethnic cleansing often appear to be unpredictable and chaotic, they nonetheless underlie a socio-logic across time and space. As the field of study evolved, scholars debated the role of authority and ideology in enabling violence. Today, consensus has shifted away from deterministic explanations about intrinsic hatred engrained in particular groups to sociological factors. They include the role of political regimes, war, organization, and narratives of ethnic hatred, each of which can play a role in facilitating violence.
Recent developments also include the creation of new institutional mechanisms that seek to punish perpetrators and prevent the occurrence of genocide and ethnic cleansing. Among them are criminal justice responses that work potentially through deterrence, but also—more fundamentally—through the initiation of cultural change. Prosecutions, as well as supplemental mechanisms such as truth commissions, may indeed lead to a radical shift in the perception of mass violence and those responsible for it, thereby delegitimizing genocidal and ethnic cleansing campaigns.