Since 1948, the United Nations has sponsored virtually every third party peacekeeping mission on Arab· Israeli fronts. Three recent events, however, have been responsible for significantly altering the pattern of peacekeeping in the region: the Camp David accords, which, because they were opposed in the U.N. by the Soviet Union and most Arab nations, prevented U.N. sponsorship of a Sinai peacekeeping force; the June 1982 Israeli invasion of Lebanon, during which the U.N. Interim Force was made to look ineffectual; and the Sabra-Shatila massacres in South Beirut three months later, which prompted the deployment of a multinational peacekeeping force. Dr.Pelcovits analyzes these events to answer the questions they raise about peacekeeping in the Middle East: What advantages are afforded by U.N. peacekeepers compared with non-U.N. missions? What net benefits are derived from American participation in a non-U.N. multinational operation? And how do they compare to the classic U.N. peacekeeping rationale of insulating disputed areas from super power confrontation? Finally, what determines the success of such operations-geopolitical circumstance or institutional affiliation?