Division of the United Nations whose primary purpose is to maintain international peace and security.
The Security Council originally consisted of five permanent members
Taiwan (succeeded in 1971 by China), France, the United Kingdom, the U.S., and the Soviet Union (succeeded in 1991 by Russia)
and six rotating members elected by the United Nations General Assembly for two-year terms. In 1965 the number of nonpermanent members was increased to 10. UN members agree to abide by the Security Council's resolutions when they join. The Security Council investigates disputes that threaten international peace and advises on how to resolve them. To prevent or halt aggression, it may impose diplomatic or economic sanctions or authorize the use of military force. Each of the permanent members holds veto power in decisions on substantive matters, such as the application of sanctions. Decisions on both substantive and procedural matters require nine affirmative votes, including the affirmative vote of all five permanent members (though in practice a permanent member may abstain without impairing the validity of a decision).