Following the establishment of the State of Israel, the 1948 Arab-Israeli war broke out. As a result, 700,000 Palestinians were forced out of their homeland to other Arab nations. The event is remembered by the Arab world as the Nakba or “catastrophe”
There had been tension and conflict between the Arabs and the Jews, and between each of them and the British forces, ever since the 1917 Balfour Declaration and the 1920 creation of the British Mandate of Palestine. British policies dissatisfied both Arabs and Jews. The Arabs’ opposition developed into the 1936–1939 Arab revolt in Palestine, while the Jewish resistance developed into the Jewish insurgency in Palestine(1944–1947). In 1947 these ongoing tensions erupted into civil war, following the 29 November 1947 adoption of the United Nations Partition Plan for Palestine, which planned to divide Palestine into three areas: an Arab state, a Jewish state and the Special International Regime for the cities of Jerusalem and Bethlehem.
On 15 May 1948, the ongoing civil war transformed into an inter-state conflict between Israel and the Arab states, following the Israeli Declaration of Independence the previous day. A combined invasion by Egypt, Jordan and Syria, together with expeditionary forces from Iraq, entered Palestine – Jordan having declared privately to Yishuv emissaries on 2 May that it would abide by a decision not to attack the Jewish state.The invading forces took control of the Arab areas and immediately attacked Israeli forces and several Jewish settlements. The 10 months of fighting, interrupted by several truce periods, took place mostly on the former territory of the British Mandate and for a short time also in the Sinai Peninsula and southern Lebanon.
As a result of the war, the State of Israel controlled both the area that the UN General Assembly Resolution 181 had recommended for the proposed Jewish state as well as almost 60% of the area of Arab state proposed by the 1948 Partition Plan, including the Jaffa, Lydda and Ramle area, Galilee, some parts of the Negev, a wide strip along the Tel Aviv–Jerusalem road, West Jerusalem and some territories in the West Bank. Transjordan took control of the remainder of the former British mandate, which it annexed, and the Egyptian military took control of the Gaza Strip. At the Jericho Conference on 1 December 1948, 2,000 Palestinian delegates called for unification of Palestine and Transjordan as a step toward full Arab unity.No state was created for the Palestinian Arabs.
The conflict triggered significant demographic change throughout the Middle East. Around 700,000 Palestinian Arabs fled or were expelled from their homes in the area that became Israel, and they became Palestinian refugees in what they refer to as Al-Nakba (“the catastrophe”). In the three years following the war, about 700,000 Jews immigrated to Israel, with many of them having been expelled from their previous countries of residence in the Middle East.