United Nations (UN)

26 June 1945; effective - 24 October 1945

to maintain international peace and security and to promote cooperation involving economic, social, cultural, and humanitarian problems

constituent organizations - the UN is composed of six principal organs and numerous subordinate agencies and bodies as follows:

1) Secretariat

2) General Assembly: International Computing Center (ICC), International Trade Center (ITC), Joint United Nations Program on HIV/AIDS (UN-AIDS), Office of the United Nations High Commissioner for Refugees (UNHCR), United Nations Capital Development Fund (UNCDF), United Nations Center for Human Settlements (UN-Habitat), United Nations Children's Fund (UNICEF), United Nations Conference on Trade and Development (UNCTAD), United Nations Development Program (UNDP), United Nations Environment Program (UNEP), United Nations Institute for Disarmament Research (UNIDIR), United Nations Institute for Training and Research (UNITAR), United Nations Interregional Crime and Justice Research Institute (UNICRI), United Nations International Strategy for Disaster Reduction (UNISDR), United Nations Office on Drugs and Crime (UNODC), United Nations Population Fund (UNFPA), United Nations Office of Project Services (UNOPS), United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA), United Nations Research Institute for Social Development (UNRISD), United Nations System Staff College (UNSSC), United Nations University (UNU), United Nations Women, United Nations Volunteers (UNV),  World Food Program (WFP)

3) Security Council: International Criminal Tribunal for the Former Yugoslavia (ICTY) (1995-2012), International Criminal Tribunal for Rwanda (ICTR) (1993-2012), United Nations Compensation Commission, United Nations Disengagement Observer Force (UNDOF), African Union/United Nations Hybrid Operation in Darfur (UNAMID), United Nations Assistance Mission in Afghanistan (UNAMA), United Nations Interim Administration Mission in Kosovo (UNMIK), United Nations Interim Force for Abyei (UNIFSA), United Nations Interim Force in Lebanon (UNIFIL), United Nations Mission in Liberia (UNMIL) (2003-2018), United Nations Military Observer Group in India and Pakistan (UNMOGIP), United Nations Multidimensional Integrated Stabilization Mission in Mali (MINUSMA), United Nations Operation in Cote d'Ivoire (UNOCI) (2004-2016), United Nations Mission for the Referendum in Western Sahara (MINURSO), United Nations Mission in South Sudan (UNMISS), United Nations Organization Stabilization Mission in the Democratic Republic of the Congo (MONUSCO), United Nations Peace-Keeping Force in Cyprus (UNFICYP), United Nations Stabilization Mission in Haiti (MINUSTAH); note - in 2017, transitioned into a smaller organization (MINUJUSTH), United Nations Multidimensional Integrated Stabilization Mission in the Central African Republic, and United Nations Truce Supervision Organization (UNTSO)

4) Economic and Social Council (ECOSOC): Commission for Social Development, Commission on Crime Prevention and Criminal Justice, Commission on Narcotics Drugs, Commission on Population and Development, Commission on Science and Technology for Development, Commission on Sustainable Development, Commission on the Status of Women, Economic and Social Commission for Asia and the Pacific (ESCAP), Economic and Social Commission for Western Asia (ESCWA), Economic Commission for Africa (ECA), Economic Commission for Europe (ECE), Economic Commission for Latin America and the Caribbean (ECLAC), Statistical Commission, Food and Agriculture Organization of the United Nations (FAO), International Atomic Energy Agency (IAEA), Preparatory Commission for the Nuclear-Test-Ban Treaty Organization (CTBTO), International Bank for Reconstruction and Development (IBRD), International Center for Secretariat of Investment Disputes (ICSID), International Civil Aviation Organization (ICAO), International Development Association (IDA), International Finance Corporation (IFC), International Fund for Agricultural Development (IFAD), International Labor Organization (ILO), International Maritime Organization (IMO), International Monetary Fund (IMF), International Telecommunication Union (ITU), Multilateral Investment Guarantee Agency (MIGA), Statistical Commission, United Nations Educational, Scientific, and Cultural Organization (UNESCO), United Nations Forum on Forests, United Nations Industrial Development Organization (UNIDO), Universal Postal Union (UPU), World Health Organization (WHO), World Intellectual Property Organization (WIPO), World Meteorological Organization (WMO), World Tourism Organization (UNWTO), and World Trade Organization (WTO), United Nations Office on Drugs and Crime (UNODC), World Bank Group (WBG), Statistical Commission, UN Forum on Forests

5) Trusteeship Council (inactive; no trusteeships at this time)

6) International Court of Justice (ICJ)

UN members -
(193) Afghanistan, Albania, Algeria, Andorra, Angola, Antigua and Barbuda, Argentina, Armenia, Australia, Austria, Azerbaijan, The Bahamas, Bahrain, Bangladesh, Barbados, Belarus, Belgium, Belize, Benin, Bhutan, Bolivia, Bosnia and Herzegovina, Botswana, Brazil, Brunei, Bulgaria, Burkina Faso, Burma, Burundi, Cabo Verde, Cambodia, Cameroon, Canada, Central African Republic, Chad, Chile, China, Colombia, Comoros, Democratic Republic of the Congo, Republic of the Congo, Costa Rica, Cote d'Ivoire, Croatia, Cuba, Cyprus, Czechia, Denmark, Djibouti, Dominica, Dominican Republic, Ecuador, Egypt, El Salvador, Equatorial Guinea, Eritrea, Estonia, Eswatini, Ethiopia, Fiji, Finland, France, Gabon, The Gambia, Georgia, Germany, Ghana, Greece, Grenada, Guatemala, Guinea, Guinea-Bissau, Guyana, Haiti, Honduras, Hungary, Iceland, India, Indonesia, Iran, Iraq, Ireland, Israel, Italy, Jamaica, Japan, Jordan, Kazakhstan, Kenya, Kiribati, North Korea, South Korea, Kuwait, Kyrgyzstan, Laos, Latvia, Lebanon, Lesotho, Liberia, Libya, Liechtenstein, Lithuania, Luxembourg, Madagascar, Malawi, Malaysia, Maldives, Mali, Malta, Marshall Islands, Mauritania, Mauritius, Mexico, Federated States of Micronesia, Moldova, Monaco, Mongolia, Montenegro, Morocco, Mozambique, Namibia, Nauru, Nepal, Netherlands, NZ, Nicaragua, Niger, Nigeria, North Macedonia,Norway, Oman, Pakistan, Palau, Panama, Papua New Guinea, Paraguay, Peru, Philippines, Poland, Portugal, Qatar, Romania, Russia, Rwanda, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Samoa, San Marino, Sao Tome and Principe, Saudi Arabia, Senegal, Serbia, Seychelles, Sierra Leone, Singapore, Slovakia, Slovenia, Solomon Islands, Somalia, South Africa, South Sudan, Spain, Sri Lanka, Sudan, Suriname, Sweden, Switzerland, Syria, Tajikistan, Tanzania, Thailand, Timor-Leste, Togo, Tonga, Trinidad and Tobago, Tunisia, Turkey, Turkmenistan, Tuvalu, Uganda, Ukraine, UAE, UK, US, Uruguay, Uzbekistan, Vanuatu, Venezuela

observers
- (1 plus Palestine Liberation Organization) Holy See, Palestine Liberation Organization