- The Korean War (1950-1953): The UN sent a multinational force to South Korea to help repel an invasion by North Korea.
- The Vietnam War (1955-1975): The UN provided humanitarian assistance and medical supplies to both North and South Vietnam.
- The Congo Crisis (1960-1965): The UN sent a peacekeeping force to the Congo to help restore order after the country gained independence from Belgium.
- The Cuban Missile Crisis (1962): The UN helped to negotiate a peaceful resolution to the Cuban Missile Crisis, which brought the world to the brink of nuclear war.
- The Arab-Israeli Conflict: The UN has been involved in the Arab-Israeli conflict since its inception in 1948. The UN has sent peacekeeping forces to the region and has helped to broker numerous peace agreements.
- The Rwandan Genocide (1994): The UN failed to prevent the Rwandan Genocide, which resulted in the deaths of over 800,000 people.
- The Bosnian War (1992-1995): The UN sent peacekeeping forces to Bosnia to help protect civilians from ethnic cleansing and other human rights abuses.
- The Kosovo War (1998-1999): The UN authorized NATO to use force to protect ethnic Albanians in Kosovo from Serbian forces.
- The Iraq War (2003-2011): The UN did not authorize the United States-led invasion of Iraq, but it did send a peacekeeping force to the country after the invasion.
- The Syrian Civil War (2011-present): The UN has been involved in the Syrian Civil War since its inception. The UN has sent humanitarian aid to the country and has helped to negotiate a number of peace agreements.
These are just a few examples of the many conflicts that the UN has been involved in. The UN has also been involved in a number of other conflicts, such as the Angolan Civil War, the Cambodian Civil War, the Lebanese Civil War, and the Somali Civil War.