United Nations as an intergovernmental organisation, the United Countries (UN) works to preserve international peace and security, foster cordial relations among governments, promote international cooperation, and serve as a focal point for harmonising the activities of nations throughout the world. It is the world's biggest and most well-known international organisation. It was founded in 1945. International territory is home to the United Nations' headquarters in New York City, which is also home to its other major offices in Geneva and Nairobi, as well as Vienna and The Hague.
As a result of World War II, the United Nations was created with the goal of avoiding future conflicts, as a successor to the ineffectual League of Nations. Approximately 50 countries gathered in San Francisco on April 25, 1945, to begin writing the United Nations Charter, which was approved on June 25, 1945, and went into force on October 24, 1945, when the United Nations commenced operations. According to the organization's charter, its goals include preserving international peace and security, safeguarding human rights, providing humanitarian assistance, promoting sustainable development, and enforcing international law, among others. The United Nations initially had 51 member nations; with the admission of South Sudan in 2011, the total number of members has increased to 193, representing almost all of the world's sovereign governments.
The Cold War between the United States and the Soviet Union, as well as their respective allies, made the organization's goal to maintain global peace more difficult to accomplish in its early decades. As a result, its operations have mainly comprised of non-combatants and lightly armed soldiers who have been assigned to monitoring, reporting, and confidence-building duties. Following extensive decolonization, which began in the 1960s, the United Nations membership increased substantially. Since then, 80 former colonies have achieved their independence, including 11 trust territories that were under the supervision of the Trusteeship Council at the time of their independence. By the 1970s, the United Nations' budget for economic and social development programmes had surpassed its budget for peacekeeping operations by a wide margin. Following the conclusion of the Cold War, the United Nations (UN) changed and expanded its field activities, taking on a broad range of difficult missions.