One argument is that intervention by the United States and its allies has been successful in stopping acts of ethnic cleansing and genocide in the past. NATO intervention in the form of a bombing campaign and later the deployment of peacekeeping troops helped end a brutal conflict in the former Yugoslavia, one in which ethnic Serbs attempted to forcibly remove or murder Bosnian Muslims. The possibility of success must be a criteria for any military intervention, and the United States and its allies have proven in the past that they were capable of using military action to avert acts of genocide. Another reason might be that United Nations peacekeepers have often proven to be insufficient to avert genocide, as in the case of Rwanda. UN peacekeepers are often saddled with restrictions that an offensive military campaign does not have. Military intervention by a powerful force like that of the United States may be the only way to crush the infrastructure that supports the mass killing of people.