"The civil war in Mandatory Palestine became a war between separate states with the declaration of the establishment of the State of Israel on 14 May 1948, a few hours before the termination of the British Mandate of Palestine at midnight. The following morning, the regular armies of neighbouring Arab states – Egypt, Transjordan and Syria – invaded territories of the former Palestinian mandate allocated for a future Arab state according to the United Nations Partition Plan for Palestine."

"On December 31, 1947, having recruited a few thousand volunteers, Abd al-Qadir al-Husayni organized the blockade of the 100,000 Jewish residents of Jerusalem.[34] To counter this, the Yishuv authorities tried to supply the city with convoys of up to 100 armoured vehicles, but the operation became more and more impractical as the number of casualties in the relief convoys surged. By March, Al-Husayni's tactic had paid off. Almost all of the Haganah's armoured vehicles had been destroyed, the blockade was in full operation, and hundreds of Haganah members who had tried to bring supplies into the city were killed.[35] The situation for those who dwelt in the Jewish settlements in the highly isolated Negev and North of Galilee was even more critical."

https://en.wikipedia.org/wiki/1948_Arab%E2%80%93Israeli_War