Massive violations of humanitarian law during the fighting in the former Yugoslavia led the Security Council in 1993 to establish an international tribunal to try persons accused of war crimes in that conflict. In 1994, the Council set up a second tribunal to hear cases involving accusations of genocide in Rwanda. The tribunals have found several defendants guilty and sentenced them to prison. The Rwanda Tribunal in 1998 handed down the first-ever verdict by an international court on the crime of genocide, as well as the first-ever sentence for that crime.
A key United Nations goal — an international mechanism to impose accountability in the face of mass violations of human rights — was realized in 1998 when governments agreed to establish an International Criminal Court. The Court provides a means for punishing perpetrators of genocide and other crimes against humanity. In voting to set up the Court, the international community made it clear that impunity — the assumption that crimes will go unpunished — is no longer possible for those who commit atrocities. The Statute of the Court entered into force on 1 July 2002.
The UN has also contributed to the elaboration of conventions relating to international humanitarian law, such as the 1948 Convention on Genocide and the 1980 Inhumane Weapons Convention (concerning weapons which are excessively injurious or have indiscriminate effects).