International efforts to solve the Arab-Zionist conflict began in the 1930s when the flight of European Jews to Palestine agitated Palestinian Arab nationalists, who feared that Arabs would soon become a minority in Palestine. Since 1948 the Arabs and Israelis have fought five major wars of attrition and terrorism, turning the Middle East into one of the most explosive regions in the world. During the Cold War especially, the intervention of outside powers has resulted in periodic international tensions, at times severe. The years between 1950 and 1967 marked a progressive decline in Soviet-Israeli relations and the culmination of a Soviet-Arab coalition. Until the end of the Cold War, the free flow of oil from the Middle East to the industrial world was second in importance to East-West relations. The first incident to indicate the effect the Arab-Israeli conflict can have on Western access to oil from the Middle East occurred between November 1956 and March 1957.