United Nations

The formal establishment of the United Nations followed the systemic collapse of the League of Nations, an organization inaugurated in 1920 that proved unable to prevent the territorial expansions of Japan, Italy, and Germany during the 1930s. While the League of Nations officially dissolved in 1946, its failure to mediate the Second Italo-Ethiopian War and the Japanese invasion of Manchuria necessitated a more robust security framework.

Initial diplomatic efforts began during the Second World War with the Declaration of St James's Palace in June 1941 and the subsequent Atlantic Charter. The term "United Nations" was first formally employed in the Declaration by United Nations on January 1, 1942, when representatives from 26 nations pledged to uphold the principles of the Allies against the Axis powers. This wartime alliance served as the precursor to a permanent international body.

Between August and October 1944, representatives from the United States, the United Kingdom, the Soviet Union, and the Republic of China met at the Dumbarton Oaks Conference in Washington, D.C. to negotiate the organization's structure. These deliberations culminated in the United Nations Conference on International Organization, which convened in San Francisco on April 25, 1945. Over two months, delegates from 50 nations drafted the United Nations Charter.

The United Nations Charter was signed on June 26, 1945, and the organization officially commenced operations on October 24, 1945, following ratification by the five permanent members of the Security Council. Although several cities were considered for the organization's base, the General Assembly accepted a donation of land from John D. Rockefeller Jr. to establish a permanent headquarters in New York City, which was completed in 1952.