United Nations Peacekeeping Forces, international armed forces first used in 1948 to observe cease-fires in Kashmir and Palestine. Although not specifically mentioned in the United Nations (UN) Charter, the use of international forces as a buffer between warring parties pending troop withdrawals and negotiations—a practice that became known as peacekeeping—was formalized in 1956 during the Suez Crisis between Egypt, Israel, France, and the United Kingdom. Although peacekeeping missions have taken many forms, they have in common the fact that they are designed to be peaceful, that they involve troops from several countries, and that the troops serve under the authority of the UN Security Council. The UN Peacekeeping Forces were awarded the 1988 Nobel Prize for Peace.