The mandates also set one of the most tragic and intractable conflicts of modern times: the conflict over Palestine which has, since 1948, ignited four wars, sent masses of Palestinian Arabs into exile, contributed to the energy crisis of 1973, and, from 1975 on, fueled the civil war in Lebanon.The conflict over Palestine actually goes back to 1896, when Theodor Herzl published a pamphlet called Der Judenstaat in which he advocated British-backed Jewish colonization in Argentina or Palestine. Herzl's writings and personal advocacy led to a political movement dedicated to the creation of such a state, and eventually focusing on Palestine. The Zionist claim to Palestine was mainly based on the fact that there had been periods of Hebrew rule in Canaan and the land west of the Jordan River between 1300 B.C. and A.D. 70.The Arabs considered this claim to be without substance.Palestine, they pointed out, had been part of the Islamic world almost continually for twelve centuries; from 636 to the First World War. In 1917, however, Lord Balfour, the British Foreign Secretary, issued the Balfour Declaration, which promised British support for the establishment of a "national home for the Jewish people" in Palestine providing that "nothing shall he done which may prejudice the civil and religious rights of existing non-Jewish communities" - a reference to the Arabs, who then were 92 percent of the population. The declaration was interpreted by key Zionist leaders as support for a sovereign Jewish state, but this interpretation has been disputed. Both Winston Churchill and Lord Balfour himself later said publicly that "a national home" meant a cultural or religious center. Establishment of a national home did not imply a Jewish state, the commission said.During the British mandate Jewish immigration increased. In the 1930s - with the rise of Adolf Hitler - and after World War II, Jewish immigration increased still further. As British efforts to control it generated widespread disapproval in the West and stimulated underground warfare by militant Zionist units against British forces, Britain eventually placed the problem in the hands of the United Nations, which in 1947 voted to partition Palestine into Jewish and Arab States.War broke out again in 1956, 1967, and 1973. In order to settle the conflict, numerous United Nations Resolutions have been passed calling for peace, the return of the refugees to their homes, Israeli withdrawal from occupied territories, and the establishment of permanent boundaries. Several Western nations have attempted mediation. President Sadat of Egypt traveled to Jerusalem and appeared before the Israeli parliament in an unprecedented peace initiative. President Carter of the United States brought the leaders of Egypt and Israel together in the United States and himself traveled to the Middle East to conclude a peace treaty, and in March 1979 Egypt and Israel signed a treaty to which the United States was also a signatory. Although it led to an improvement in Egyptian-Israeli relations which resulted in Israeli evacuation of some occupied Egyptian territory however, this separate peace treaty did nothing to bring about withdrawal of Israeli occupation forces from East Jerusalem, the West Bank, and the Golan Heights of Syria and left untouched the root cause of the entire problem- that is, the status of the Palestinians. The immediate net result of the treaty, in fact, was a general increase in tension in the Middle East which manifested itself in an apparent increase in Israeli intransigence in the occupied territories and the isolation of Egypt from the rest of the Arab world and it failed to achieve a permanent and comprehensive peace.