United Nations
Members of the United Nations Security Council sit during a meeting on Syria at the United Nations Headquarters in New York City on April 5, 2017.
Source: Shannon Stapleton/Reuters
Year established: 1945
Member countries: 193 (2 nonmember states, the Holy See and the State of Palestine, are permanent observers)
Mission: To promote international peace and stability, human rights, and economic development
You know this organization for: the many specialized agencies under its umbrella, including the UN Children’s Fund (UNICEF), the UN Educational, Scientific, and Cultural Organization (UNESCO), the World Bank, the World Health Organization (WHO), and more. Members of the UN Security Council, one of the institution’s six principal organs, focus on maintaining international peace and security.
North Atlantic Treaty Organization (NATO)
Members of the Montenegrin guard of honor inspect NATO and Montenegro flags prior to a ceremony to mark the accession to NATO of Montenegro in Podgorica, Montenegro on June 7, 2017.
Source: Stevo Vasiljevic/Reuters
Year established: 1949
Member countries: 30 in North America and Europe, including Turkey (expanded from 12 when NATO was founded)
Mission: To safeguard its members’ freedom and security by both political and military means
You know this organization for: Article 5, which establishes the principle of collective defense, committing each members to defend any other that is attacked. While Article 5 has been invoked only once, NATO has used the principle to intervene in conflicts many times over the last several decades, including in Afghanistan, the Balkans, and Libya.
European Union (EU)
Anti-Brexit protesters stand next to an illuminated sign outside the Houses of Parliament in London on December 10, 2018.
Source: Henry Nicholls/Reuters
Year established: 1993
Member countries: 27
Mission: To help member countries cooperate on economic, political, and security matters
You know this organization for: the United Kingdom’s withdrawal from the EU (commonly known as Brexit). The EU helps its members by removing trade barriers, sharing a common currency (nineteen of its twenty-seven members use the euro), and allowing EU citizens to move freely among many member countries.
World Trade Organization (WTO)
Protesters block a police line from moving forward in a downtown Seattle intersection on November 30, 1999, on the first day of meetings for the World Trade Organization conference.
Source: Andy Clark/Reuters
Year established: 1995
Member countries: 164
Mission: To manage the rules of international trade and ensure the fair and equitable treatment of all members through negotiations and trade dispute settlements
You know this organization for: the products and services that you use on a daily basis—clothes, for example—that are governed by international trade. The WTO creates global trade rules and settles disputes among countries, which might disagree on the interpretation of those rules. The WTO has its detractors, so you may know the organization from demonstrations like the 1999 Seattle protests, when thousands demonstrated during the WTO ministerial conference.
Group of Twenty (G20)
Japan's Prime Minister Shinzo Abe and Argentina's President Mauricio Macri attend the plenary session at the G20 leaders summit in Buenos Aires, Argentina on December 1, 2018.
Source: G20 Argentina via Reuters
Year established: 1999
Member countries: 20 (19 individual countries and the European Union)
Mission: To convene officials from the world’s largest economies, both advanced and developing, to jointly address global economic concerns and coordinate economic policies
You know this organization for: the annual G20 summit, a series of meetings that bring together finance ministers, central bank governors, and heads of member governments to coordinate on global economic issues. For example, members of the G20 summit in the late 2000s and early 2010s helped create and implement policies to stem the 2008 global financial crisis.
International Criminal Court (ICC)
Emmanuel Altit (right), defense lawyer for former Ivory Coast President Laurent Gbagbo, talks to prosecutor Fatou Bensouda as they wait for the start of Gbagbo's trial at the International Criminal Court in The Hague, Netherlands, on January 28, 2016.
Source: Peter Dejong/Pool via Reuters
Year established: 2002 (when the Rome Statute, the treaty that created the ICC, came into force.)
Member countries: 123 (The United States signed but did not ratify the Rome Statute, which means it is not a full member. Burundi was a member but withdrew in 2017.)
Mission: To investigate and try those charged with genocide, war crimes, crimes against humanity, and crimes of aggression
You know this organization for: convicting several men for war crimes committed in Mali and the Democratic Republic of Congo. You may also know some of the situations currently under investigation, including atrocities committed in Sudan’s Darfur region and in Libya, and the actions of the Lord’s Resistance Army in Uganda.