center. The armistice lines were known afterwards as the "Green Line". The Gaza Strip and the West Bank (including East Jerusalem) were occupied by Egypt and Transjordan respectively. The United Nations Truce Supervision Organization and Mixed Armistice Commissions were set up to monitor ceasefires, supervise the armistice agreements, to prevent isolated incidents from escalating, and assist other UN peacekeeping operations in the region. Just before the signing of the Israel-Transjordan armistice agreement, general Yigal Allon proposed a military offensive to conquer the West Bank up to the Jordan River as the natural, defensible border of the state. Ben-Gurion refused, although he was aware that the IDF was militarily strong enough to carry out the conquest. He feared the reaction of Western powers and wanted to maintain good relations with the United States and not to provoke the British. More, the results of the war were already satisfactory and Israeli leaders had to build a state. Casualties Israel lost 6,373 of its people, about 1% of its population at the time, in the war. About 4,000 were soldiers and the rest were civilians. Around 2,000 were Holocaust survivors. The exact number of Arab casualties is unknown. One estimate places the Arab death toll at 7,000, including 3,000 Palestinians, 2,000 Egyptians, 1,000 Jordanians, and 1,000 Syrians. In 1958, Palestinian historian Aref al-Aref calculated that the Arab armies' combined losses amounted to 3,700, with Egypt losing 961 regular and 200 irregular soldiers and Transjordan losing 362 regulars and 200 irregulars. According to Henry Laurens, the Palestinians suffered double the Jewish losses, with 13,000 dead, 1,953 of whom are known to have died in combat situations. Of the remainder, 4,004 remain nameless but the place, tally and date of their death is known, and a further 7,043, for whom only the place of death is known, not their identities nor the date of their death. According to Laurens, the largest part of Palestinian casualties consisted of non-combatants and corresponds to the successful operations of the Israelis. Demographic outcome in Palestine During the 1947–1948 Civil War in Mandatory Palestine and the 1948 Arab–Israeli War that followed, around 750,000 Palestinian Arabs fled or were expelled from their homes, out of approximately 1,200,000 Arabs living in former British Mandate of Palestine, a displacement known to Palestinians as the Nakba. In 1951, the UN Conciliation Commission for Palestine estimated that the number of Palestinian refugees displaced from Israel