<P> The leaders of the UN had high hopes that it would act to prevent conflicts between nations and make future wars impossible . Those hopes have obviously not fully come to pass . From about 1947 until 1991 the division of the world into hostile camps during the Cold War made agreement on peacekeeping matters extremely difficult . Following the end of the Cold War, renewed calls arose for the UN to become the agency for achieving world peace and co-operation, as several dozen active military conflicts continued to rage across the globe . The breakup of the Soviet Union has also left the United States in a unique position of global dominance, creating a variety of new problems for the UN (See the United States and the United Nations). </P> <P> In December 1945, the US Senate and the US House of Representatives, by unanimous votes, requested that the UN make its headquarters in the United States . The UN accepted this suggestion and, after considering sites in the Black Hills, Flushing Meadows--Corona Park, Navy Island and what would become the World Trade Center site, constructed the United Nations headquarters building in New York City in 1949 and 1950 beside the East River on land purchased with an $8.5 million donation from John D. Rockefeller, Jr . The UN headquarters officially opened on January 9, 1951, although construction was not formally completed until October 9, 1952 . </P> <P> Under special agreement with the United States, the UN enjoys certain diplomatic privileges and immunities, but generally the laws of New York City, New York State, and the United States apply . </P> <P> While the principal headquarters of the UN remain in New York City, major agencies base themselves in Geneva, The Hague, Vienna, Nairobi and elsewhere . </P>

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