The United Nations Organization (UN, UN)… is the most comprehensive attempt in the history of Humanity to create an IO (International Organization) that aims to maintain international peace and security as the first and foremost of its purposes. The UN is, without a doubt, the clearest example of a universal organization, since today, after a broad process of incorporation of new members, it is made up of practically all the existing States.

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The UN is an international organization created by states through its Constitutive Treaty, known as the Charter of the United Nations, or Charter of San Francisco , and forms an international political structure capable of transforming itself and could even legally disappear, as happened to the League of Nations; although this latter eventuality is not foreseen in its Constitutive Treaty, whose validity is theoretically indefinite.

(Excerpt from the book International Organizations by the great internationalist Manuel Diez de Velasco ).