groups, militias, and armies is necessary because genocide is a group crime; prevention concentrates on outlawing hate groups and prosecuting hate crimes; "Polarization" of the population, so that genocide becomes popularly supported, is necessary to empower the perpetrators. It often means driving out, arresting, or killing moderates who might oppose genocide from within the perpetrator group; prevention requires physical and legal protection of moderates from arrest and detention; "Preparation" - planning of the genocide by leaders of the killers - usually occurs secretly; prevention is best achieved by arresting leaders who incite or conspire to commit genocide, imposing sanctions on them, and supporting resistance to them; "Persecution" of the victim group through massive violation of their fundamental human rights means genocidal massacres may follow; prevention requires targeted sanctions on leaders of regimes that commit crimes against humanity, including prosecution in international and national courts, diplomatic pressure, economic sanctions, and preparation for regional intervention. "Extermination" is the stage in the genocidal process that international law officially recognizes as "genocide". However, mass killing is not the only act recognized as genocide in the Genocide Convention. Causing severe bodily or mental harm to members of the group, deliberately inflicting conditions of life intended to physically destroy the group, imposing measures intended to prevent births within the group, and forcibly transferring children of the group to another group are also acts of genocide outlawed by the Genocide Convention. At this stage targeted sanctions and credible diplomatic threats may reduce a genocide. But support for internal resistance and acceptance of refugees is also usually required. Stopping genocide against the will of national leaders normally requires their overthrow from within, or armed intervention under Chapter 7 of the UN Charter or by regional organizations acting under UN Charter Chapter 8. Every genocide begins and ends in Denial by the perpetrators and their successors. Denial is best countered by ample reporting of facts during a genocide by journalists, other media, human rights organizations, UN Commissions of Inquiry, and world leaders. After a genocide, denial may be countered by trials of the perpetrators, truth commissions, educational programs, memorials, museums, films and other media. These early warning signs are common in nearly every genocide, but their identification is only useful in prevention efforts when actual actions are taken to combat them. One salient example of a failure to act on early warning signs is the Rwandan genocide. Despite numerous