why was the state of Israel established in 1948?

Before understanding the establishment of the state of Israel, it must first be understood about how the Israelites come from. Most of them are Jews, who once established a country (with a judge, and later a king as the ruler) in Canaan (now the land of Israel/Palestine) from about 14th century B.C. to 586 B.C.. After the demolition of the country by the Babylonian king Nebucharnezzar in 586 B.C., the Jews didn't have a country of their own. However, some of them were still permitted to live in Palestine. A short-lived kingdom was once established by Macabbi family from 2nd century to 1st century B.C. for the Jews themselves before they were under the rule of the Roman Empire. It was not until A.D. 70 that the Jews were forced by the Roman government to evacuate from Palestine.

From A.D. 70 onwards, Jews were scattered around the world without a permanent settlement and not welcomed by other people. In late 19th century A.D., some Jews initiated a movement called Zionism, which aimed at re-establishment of the state of Israel in Palestine, in which Palestinians (Arab descendants) had settled for more than a thousand years. As a consequence, numerous Jews moved from other parts of the world to Palestine for settlement, while Palestine was under the rule of the weakening Ottoman Empire. After the breakdown of the Ottoman Empire in 1918, Palestine became a British mandate and the immigration of Jews became more intense.

However, the influx of the Jews led to the social problems between themselves and Palestinians, who are different in culture and religion. To avoid further clashes, the British government limited the number of Jewish immigrants, though some of the Jews chose to come by illegal immigration.

After the event of Holocaust, the world was generally sympathetic towards the Jews who escaped from extermination by Nazi regime. Therefore, Jews were allowed to immigrate in Palestine in great numbers. For the settlement of the dispute between the Jews and the Palestinians, the United Nations proposed the partition of Palestine into a Jewish state and a Palestinian state in 1947. Jews welcomed the proposal, but Palestinians objected because they thought they could expel the Jews by force.

On 14th May 1948, Ben Gurion and the first cabinet of the Israeli government announced the establishment of the state of Israel without prior notice as an attempt to gain the support from the world. The Palestinians allied with many other Arab states in Middle East including Jordan, Egypt and Syria to declare war on Israel, and attempted to "push the Jews to the Mediterranean Sea". However, the newly formed Israeli army succeeded in defeating their enemies in the war between 1948 and 1949. After that, the state of Israel stood firm on the land of Palestine and the Palestinians became a race without a government of their own.