The Syrian intervention will be treated as an event in the tradition of the quasi-experimental research of Campbell and Ross (1968), Caporaso and Pelowski (1971), Hibbs (1977), and Glass (1968) who have used the interrupted time-series design to assess the impact of a discrete historical event on a behavioral process. The Syrian military intervention occurred during the first 10-day period of June 1976; and the Syrian military offensive against the Palestinians and leftists did not end until the October 1976 Riyadh Conference. During the conference the Syrian military presence was legitimized through the establishment of the Arab Deterrent Force. Hence, the role of the Syrian forces changed from a military action to peace-keeping. Here, Syrian intervention will be associated with the period of the military action.