Proposed separation of Palestine
On 29 November 1947, the United Nations General Assembly adopted a resolution recommending the adoption and implementation of a plan to partition the British Mandate of Palestine into two states, one Arab and one Jewish, and the City of Jerusalem.
The General Assembly resolution on Partition was greeted with overwhelming joy in Jewish communities and widespread outrage in the Arab world. In Palestine, violence erupted almost immediately, feeding into a spiral of reprisals and counter-reprisals. The British refrained from intervening as tensions boiled over into a low-level conflict that quickly escalated into a full-scale civil war.
From January onwards, operations became increasingly militarized, with the intervention of a number of Arab Liberation Army regiments inside Palestine, each active in a variety of distinct sectors around the different coastal towns. They consolidated their presence in Galilee and Samaria. Abd al-Qadir al-Husayni came from Egypt with several hundred men of the Army of the Holy War. Having recruited a few thousand volunteers, al-Husayni organized the blockade of the 100,000 Jewish residents of Jerusalem. 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-Hussayni's tactic had paid off. Almost all of 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. The situation for those who dwelt in the Jewish settlements in the highly isolated Negev and North of Galilee was even more critical.
While the Jewish population had received strict orders requiring them to hold their ground everywhere at all costs, the Arab population was more affected by the general conditions of insecurity to which the country was exposed. Up to 100,000 Arabs, from the urban upper and middle classes in Haifa, Jaffa and Jerusalem, or Jewish-dominated areas, evacuated abroad or to Arab centres eastwards.
This situation caused the United States to withdraw its support for the Partition plan, thus encouraging the Arab League to believe that the Palestinian Arabs, reinforced by the Arab Liberation Army, could put an end to the plan for partition. The British, on the other hand, decided on 7 February 1948, to support the annexation of the Arab part of Palestine by Transjordan.
Although a certain level of doubt took hold among Yishuv supporters, their apparent defeats were due more to their wait-and-see policy than to weakness. David Ben-Gurion reorganized Haganah and made conscription obligatory. Every Jewish man and woman in the country had to receive military training. Thanks to funds raised by Golda Meir from sympathisers in the United States, and Stalin's decision to support the Zionist cause, the Jewish representatives of Palestine were able to sign very important armament contracts in the East. Other Haganah agents recuperated stockpiles from the Second World War, which helped improve the army's equipment and logistics. Operation Balak allowed arms and other equipment to be transported for the first time by the end of March.
Ben-Gurion invested Yigael Yadin with the responsibility to come up with a plan of offense whose timing was related to the foreseeable evacuation of British forces. This strategy, called Plan Dalet, was readied by March and implemented towards the end of April. A separate plan, Operation Nachshon, was devised to lift the siege of Jerusalem. 1500 men from Haganah's Givati brigade and Palmach's Harel brigade conducted sorties to free up the route to the city between 5 and 20 April. Both sides acted offensively in defiance of the Partition Plan, which foresaw Jerusalem as a corpus separatum, under neither Jewish nor Arab jurisdiction. The Arabs did not accept the Plan, while the Jews were determined to oppose the internationalization of the city, and secure it as part of the Jewish state. The operation was successful, and enough foodstuffs to last two months were trucked into Jerusalem for distribution to the Jewish population. The success of the operation was assisted by the death of al-Husayni in combat. During this time, and independently of Haganah or the framework of Plan Dalet, irregular fighters from Irgun and Lehi formations massacred a substantial number of Arabs at Deir Yassin, an event that, though publicly deplored and criticized by the principal Jewish authorities, had a deep impact on the morale of the Arab population and contributed to generate the exodus of the Arab population.
At the same time, the first large-scale operation of the Arab Liberation Army ended in a debacle, having been roundly defeated at Mishmar HaEmek, coinciding with the loss of their Druze allies through defection.
Within the framework of the establishment of Jewish territorial continuity foreseen by Plan Dalet, the forces of Haganah, Palmach and Irgun intended to conquer mixed zones. The Palestinian Arab society was shaken. Tiberias, Haifa, Safed, Beisan, Jaffa and Acre fell, resulting in the flight of more than 250,000 Palestinian Arabs.
The British had, at that time, essentially withdrawn their troops. The situation pushed the leaders of the neighbouring Arab states to intervene, but their preparation was not finalized, and they could not assemble sufficient forces to turn the tide of the war. The majority of Palestinian Arab hopes lay with the Arab Legion of Transjordan's monarch, King Abdullah I, but he had no intention of creating a Palestinian Arab-run state, since he hoped to annex as much of the territory of the British Mandate for Palestine as he could. He was playing a double-game, being just as much in contact with the Jewish authorities as with the Arab League.
In preparation for the offensive, Haganah successfully launched Operations Yiftah and Ben-'Ami to secure the Jewish settlements of Galilee, and Operation Kilshon, which created a united front around Jerusalem. The inconclusive meeting between Golda Meir and Abdullah I, followed by the Kfar Etzion massacre on 13 May by the Arab Legion led to predictions that the battle for Jerusalem would be merciless.
On 14 May 1948, David Ben-Gurion declared the establishment of the State of Israel and the 1948 Palestine war entered its second phase with the intervention of the Arab state armies and the beginning of the 1948 Arab–Israeli War.
By September 1947 the Haganah had "10,489 rifles, 702 light machine-guns, 2,666 submachine guns, 186 medium machine-guns, 672 two-inch mortars and 92 three-inch (76 mm) mortars".
In 1946, Ben-Gurion decided that the Yishuv would probably have to defend itself against both the Palestinian Arabs and neighbouring Arab states and accordingly began a "massive, covert arms acquisition campaign in the West", and acquired many more during the first few months of hostilities.
An Israeli Avia S-199, in June 1948
The Yishuv managed to clandestinely amass arms and military equipment abroad for transfer to Palestine once the British blockade was lifted. In the United States, Yishuv agents purchased three Boeing B-17 Flying Fortress bombers, one of which bombed Cairo in July 1948, some Curtiss C-46 Commando transport planes, and dozens of half-tracks, which were repainted and defined as "agricultural equipment". In Western Europe, Haganah agents amassed fifty 65mm French mountain guns, twelve 120mm mortars, ten H-35 light tanks, and a large number of half-tracks. By mid-May or thereabouts the Yishuv had purchased from Czechoslovakia 25 Avia S-199 fighters (an inferior version of the Messerschmitt Bf 109), 200 heavy machine guns, 5,021 light machine guns, 24,500 rifles, and 52 million rounds of ammunition, enough to equip all units, but short of heavy arms. The airborne arms smuggling missions from Czechoslovakia were codenamed Operation Balak.
The airborne smuggling missions were carried out by mostly American aviators – Jews and non-Jews – led by ex-U.S. Air Transport Command flight engineer Al Schwimmer.
Schwimmer's operation also included recruiting and training fighter pilots such as Lou Lenart, commander of the first Israeli air assault against the Arabs.
The Yishuv also had "a relatively advanced arms producing capacity", that between October 1947 and July 1948" produced 3 million 9 mm bullets, 150,000 Mills grenades, 16,000 submachine guns (Sten Guns) and 210 three-inch (76 mm) mortars", along with a few "Davidka" mortars, which had been indigenously designed and produced. They were inaccurate but had a spectacularly loud explosion that demoralized the enemy. A large amount of the munitions used by the Israelis came from the Ayalon Institute, a clandestine bullet factory underneath kibbutz Ayalon, which produced about 2.5 million bullets for Sten guns. The munitions produced by the Ayalon Institute were said to have been the only supply that was not in shortage during the war. Locally produced explosives were also plentiful. After Israel's independence, these clandestine arms manufacturing operations no longer had to be concealed, and were moved above ground. All of the Haganah's weapons-manufacturing was centralized and later became Israel Military Industries.
In November 1947, the Haganah was an underground paramilitary force that had existed as a highly organized, national force, since the Arab riots of 1920–21, and throughout the riots of 1929, Great Uprising of 1936–39, and World War 2. It had a mobile force, the HISH, which had 2,000 full-time fighters (men and women) and 10,000 reservists (all aged between 18 and 25) and an elite unit, the Palmach composed of 2,100 fighters and 1,000 reservists. The reservists trained three or four days a month and went back to civilian life the rest of the time. These mobile forces could rely on a garrison force, the HIM (Heil Mishmar, lit. Guard Corps), composed of people aged over 25. The Yishuv's total strength was around 35,000 with 15,000 to 18,000 fighters and a garrison force of roughly 20,000.
There were also several thousand men and women who had served in the British Army in World War II who did not serve in any of the underground militias but would provide valuable military experience during the war. Walid Khalidi says the Yishuv had the additional forces of the Jewish Settlement Police, numbering some 12,000, the Gadna Youth Battalions, and the armed settlers. Few of the units had been trained by December 1947.
On 5 December 1947, conscription was instituted for all men and women aged between 17 and 25 and by the end of March, 21,000 had been conscripted. On 30 March, the call-up was extended to men and single women aged between 26 and 35. Five days later, a General Mobilization order was issued for all men under 40.
The Irgun, whose activities were considered by MI5 to be terrorism, was monitored by the British.
By March 1948, the Yishuv had a numerical superiority, with 35,780 mobilised and deployed fighters for the Haganah, 3,000 of Stern and Irgun, and a few thousand armed settlers.
The effective number of Arab combatants is listed at 12,000 by some historians while others calculate a total Arab strength of approximately 23,500 troops, and with this being more of less or roughly equal to that of the Yishuv. However, as Israel mobilized most of its most able citizens during the war while the Arab troops were only a small percentage of its far greater population, the strength of the Yishuv grew steadily and dramatically during the war.
According to Benny Morris, by the end of 1947, the Palestinians "had a healthy and demoralising respect for the Yishuv's military power" and if it came to battle the Palestinians expected to lose.