The United Nations (UN) is an intergovernmental organization to promote international co-operation. A replacement for the ineffective League of Nations, the organization was established on October 24, 1945 after World War II in order to prevent another such conflict. At its founding, the UN had 51 member states; there are now 193. The headquarters of the United Nations is in Manhattan, New York City, and experiences extraterritoriality. Further main offices are situated in Geneva, Nairobi, and Vienna. The organization is financed by assessed and voluntary contributions from its member states. Its objectives include maintaining international peace and security, promoting human rights, fostering social and economic development, protecting the environment, and providing humanitarian aid in cases of famine, natural disaster, and armed conflict.The United Nations Charter was drafted at a conference between April–June 1945 in San Francisco, and was signed on June 26, 1945 at the conclusion of the conference; this charter took effect on October 24, 1945, and the UN began operation. The UN’s mission to preserve world peace was complicated in its early decades of the Cold War between the US and Soviet Union and their respective allies. The organization participated in major actions in Korea and the Congo, as well as approving the creation of the state of Israel in 1947. The organization’s membership grew significantly following widespread decolonization in the 1960s, and by the 1970s, its budget for economic and social development programs far outstripped its spending on peacekeeping. After the end of the Cold War, the UN took on major military and peacekeeping missions across the world with varying degrees of success.
The UN has six principal organs: the General Assembly (the main deliberative assembly); the Security Council (for deciding certain resolutions for peace and security); the Economic and Social Council (ECOSOC) (for promoting international economic and social co-operation and development); the Secretariat (for providing studies, information, and facilities needed by the UN); the International Court of Justice (the primary judicial organ); and the United Nations Trusteeship Council (inactive since 1994). UN System agencies include the World Bank Group, the World Health Organization, the World Food Program, UNESCO, and UNICEF. The UN’s most prominent officer is the Secretary-General, an office held by Portuguese António Guterres in 2017.