The United Nations was established on 24 October 1945 by 51 countries committed to preserving peace through international cooperation and collective security. Today, nearly every nation in the world belongs to the UN: membership totals 191 countries. When States become Members of the United Nations, they agree to accept the obligations of the UN Charter, an international treaty that sets out basic principles of international relations. According to the Charter, the UN has four purposes: to maintain international peace and security; to develop friendly relations among nations; to cooperate in solving international problems and in promoting respect for human rights; and to be a centre for harmonizing the actions of nations. The United Nations is not a world government and it does not make laws. It does, however, provide the means to help resolve international conflicts and formulate policies on matters affecting all of us. At the UN, all the Member States—large and small, rich and poor, with differing political views and social systems—have a voice and a vote in this process. The United Nations has six main organs. Five of them—the General Assembly, the Security Council, the Economic and Social Council, the Trusteeship Council and the Secretariat—are based at UN Headquarters in New York. The sixth, the International Court of Justice, is located at The Hague in the Netherlands.

This definition is in context to Iraq Crisis. See more contextual defintions for United Nations.