June 1948 to Present: The Security Council calls for a halt in the Arab-Israeli war and establishes the first UN peacekeeping operation: the UN Truce Supervision Organization (UNTSO). Military observers remain in the region to monitor ceasefires, armistice agreements and to assist in peacekeeping operations.

November 1956 to June 1957: Israel, France and the United Kingdom intervene when Egypt nationalizes the Suez Canal. An emergency meeting of the General Assembly creates the first UN armed peacekeeping force: UNEF I. The force supervises the withdrawal of invading forces and serves as a buffer between Israel and Egypt. In 1957, Egypt compels UNEF I to leave the area.

June to December 1958: The Security Council sets up the UN Observation Group in Lebanon (UNOGIL) after a violent conflict erupts between Lebanon and Syria. UNOGIL ensures arms and militia aren't crossing Lebanese borders. After tensions ease, UNOGIL withdraws.

July 1960 to June 1964: The newly independent Congo faces an army insurrection and civil disorder. The government asks for UN help. ONUC (The UN Operation in the Congo) struggles to maintain Congo's political independence while ridding the country of foreign militia. At one time, UN troops number more than 19,000.

October 1962 to April 1963: The UN sends two groups — the UN Security Force (UNSF) and the UN Temporary Executive Authority (UNTEA) – to assume responsibility over West Irian, which is in dispute between Indonesia and the Netherlands. Eventually, the Dutch allow Indonesia full administrative control. It becomes an Indonesian province in 1969.

July 1963 to September 1964: Egypt and Saudi Arabia make incursions into Yemen as a civil war threatens to de-stabilize the region. The UN brokers a disengagement agreement and sends a UN Yemen Observation Mission (UNYOM) to oversee the area.

1964 to Present: The UN Peacekeeping Force in Cyprus (UNFICYP) is set up to maintain a buffer zone between the island's Greek and Turkish residents.

October 1973 to July 1979: The UN sets up a second UN Emergency Force (UNEF II) after Syria and Egypt attack Israeli positions. UNEF II stabilizes the areas around the Suez Canal and Sinai.

June 1974 to Present: The Security Council establishes a UN Disengagement Observer Force (UNDOF) in the Golan Heights after the 1973 war between Syrian and Israeli forces. UNDOF maintains the ceasefire agreement.

March 1978 to Present: Israel invades southern Lebanon after the Palestinian Liberation Organization (PLO) launches attacks from the region. The Security Council creates UNIFIL (UN Interim Force in Lebanon) to manage Israel's withdrawal and to re-establish the Lebanese government's control over the area.

May 1988 to March 1990: The UN calls for the withdrawal of the Soviet military in Afghanistan (having invaded in 1979). A 1988 Geneva Accord commits Afghanistan and Pakistan to mutual non-interference and for the return of refugees. The organization sets up the UN Good Offices Mission in Afghanistan and Pakistan (UNGOMAP) to monitor implementation.

August 1988 to February 1991: Iran and Iraq agree to a ceasefire after eight years of war. The UN Iran-Iraq Military Observer Group (UNIIMOG) is created to monitor the situation. After both sides sign an agreement and retreat to their pre-war borders, UNIIMOG completes its mission.

January 1989 to June 1991: UN Angola Verification Mission I (UNIVEM I) is created to monitor the withdrawal of Cuban troops from Angola.

April 1991 to October 2003: The UN Iraq-Kuwait Observer Mission (UNIKOM) was established after the withdrawal of Iraqi forces from Kuwait. Its role was to monitor the Iraq-Kuwait border.

June 1991 to February 1995: UN deploys a combination force of military and civilian police to carry out agreements after 16 years of civil war in Angola. UNIVEM II helps broker peace between the government and rebels.

July 1991 to April 1995: The UN Observer Mission in El Salvador (ONUSAL) helps broker agreements to end a decade-long civil war. It oversees elections in 1993.

April 1991 to Present: In 1988, the Moroccan government agrees to a referendum allowing the people of the Western Sahara to decide the territory's political future. The UN Mission for the Referendum in Western Sahara (MINURSO) organizes a ceasefire with the territory's rebels and prepares for a referendum. Differences over key elements in the vote delay the referendum. MINURSO remains to maintain the ceasefire.

August 1993 to Present: The UN Observer Mission in Georgia (UNOMIG) is created to maintain a ceasefire between the government of Georgia and Abkhaz authorities in the country.

June 1999 to Present: The UN Mission in Kosovo (UNMIK) is set up to perform civilian administrative duties, facilitate the return of refugees and to maintain law and order.

October 1999 to present: The UN Observer Mission in Sierra Leone (UNOMSIL) provides security at government buildings and assists local law enforcement.

November 1999 to present: The UN Mission in the Democratic Republic of Congo (MONUC) monitors the ceasefire and investigates violations. Scheduled to end March 31, 2005.

July 2000 to Present: The Security Council sets up UNMEE (the UN Mission in Ethiopia and Eritrea) to keep the peace after a two-year border conflict.

May 2002 to Present: The UN Mission in Support of East Timor (UNMISET) is created after the country becomes independent on May 20. UNMISET is to provide assistance for two years.

September 2003 to Present: The UN Mission in Liberia (UNIMIL) is created to keep the peace between the warring factions in the country, support human rights and to train the police and military.

April 2004: The Security Council sets up the UN Operation in the Ivory Coast (UNOCI) to stabilize the country.