"UN Office on Genocide Prevention and the Responsibility to Protect works to prevent genocide, war crimes, ethnic cleansing and crimes against humanity....Crimes against humanity have not yet been codified in a dedicated treaty of international law, unlike genocide and war crimes, although there are efforts to do so. Despite this, the prohibition of crimes against humanity, similar to the prohibition of genocide, has been considered a peremptory norm of international law, from which no derogation is permitted and which is applicable to all States."