In order to push the unarmed defenseless Palestinian Arabs to leave their homes. Jewish terrorist groups such as Irgun Zwei Leumi were brought in when other methods failed. On 9th April 1948, the Irgun Zwei Leumi led by Menachem Beigin, a former Israeli Cabinet Minister and former leader of the Opposition in the Israeli Parliament, attacked the small Arab village of Deir Yassin near Jerusalem. An account of this barbaric massacre was given by Jacques de Reynier, the Chief Delegate of the International Red Cross , who was able to reach the village and witness the aftermath of the massacre: "Three hundred persons" he said, "were massacred ... without any military reason or provocation of any kind; old men women, children, newly-born were savagely murdered with grenades and knives by Jewish troops of the Irgun, entirely under the control of their chiefs."

The objective behind the Deir Yassin massacre was to terrify the Arab civilian population, and force them to flee to secure for the Zionists the land without the people. The plan succeeded and they fled in terror, to save their lives. Before May 15th, 1948, while the British Government was still responsible, the Jews had occupied many purely Arab cities like Jaffa and Acre and scores of villages that were in the territory assigned by the U.N. Resolution for the Arab State and evicted more than 300,000 inhabitants from their homes. In an attempt to stem this tide, the neighboring Arab states sent their armies on 15th May 1948 into Palestine. On 15th July 1948 the U.N. imposed a final truce between Israel and the Arabs, by which time Israel had occupied an even larger part of the territory allotted to the Arab State in Palestine.