The vote by the United Nations to approve the Partition Plan sparked celebrations across Jewish Palestine, as a long-held dream was nearing realization. Golda Meir, who would later become Prime Minister, addressed the jubilant crowds gathered in front of the Jewish Agency building in Jerusalem, saying:

For two thousand years we have waited for our deliverance. Now that it is here it is so great and wonderful that it surpasses human words. Mazel Tov!

While the approval of the Partition Plan was celebrated, many were acutely aware that the greatest challenge lay ahead. David Shatiel commander of the Haganah captured this sentiment in his diary entry on the night of the 29th, following the UN Partition Plan vote: “None of us knows what might happen tomorrow.”

The very next day, a Jaffa-based band of terrorists launched an attack on a bus carrying Jewish passengers. On December 5th, the British government announced its intention to withdraw all of their troops from the region by May 15th, adopting a stance of neutrality in the ensuing fight between the Jewish and Arab communities. Despite their declared neutrality, both sides expressed grievances about the British actions during this transitional period.
 
During December, many mixed areas saw population shifts and the establishment of clear demarcation lines. It is estimated that during this period 100,000 Arabs either left the country or left their homes in the mixed towns and went back to their ancestral villages.

At the beginning of January, members of the Arab Liberation Army, primarily consisting of Palestinians trained by neighboring Arab states, entered the region without British intervention. On January 10, they attacked the settlement of Kfar Szold, but were repelled. Jewish settlements throughout the country became isolated, necessitating significant efforts to provide them with supplies.

Even Jerusalem faced immense challenges in receiving supplies. One particularly famous and tragic event was the effort to reinforce the settlements of Kfar Etzion near Jerusalem, which had been severed from Jewish forces. A platoon of 35 soldiers was sent dispatched on foot to bolster the Etzion bloc settlements. En route, the force was detected and ambushed — resulting in the death of all 35 of the soldiers. This force became posthumously known as the “Lamed Hay” (35 in Gematria).

By March, the momentum of battle seemed to be shifting against the Jews. The crucial access route to Jerusalem had become impassible. During this period, Jewish forces adopted a predominantly defensive posture, only undertaking offensive operations on a local basis. These military setbacks led to a wavering of support from the United States for the Partition Plan. America’s UN Ambassador, seemingly acting without President Truman’s approval, proposed a postponement of the Partition Plan, in favor of placing Palestine under UN trusteeship.

As the situation deteriorated, Ben Gurion demanded that the military adopt an offensive strategy to clear the route to Jerusalem. This shift became feasible thanks to the successful smuggling of large quantities of small arms into the country. For the first time, troops were fully equipped, without the need to share rifles and machine guns.

The first major offensive, called “Operation Nachshon,” aimed to establish a corridor along the road to Jerusalem, and thus secure this vital route. The key battle along the road was the fight for Kastel, which Haganah forces won after intense combat on April 10. During the battle, Abd al-Qadir Husayni, the mufti military leader, was killed. This effectively ended the involvement of the Mufti's forces in the war. While the capture of the Kastel was a critical achievement, the operation’s broader objectives included taking control of all the Arab villages that served as bases for forces attacking the convoys to Jerusalem.

The attack on Deir Yassin, a village on the outskirts of Jerusalem, was assigned to the Irgun, under the command of Menachem Begin. The operation which took place on April 9th, encountered fierce resistance, culminating in intense house-to-house combat, which included indiscriminate attacks on houses that were inhabited by women and children. This fighting resulted in the deaths to 100-120 villagers, fatality numbers that were swiftly exaggerated in subsequent reports. However, the impact of Deir Yassin extended far beyond the immediate tactical victory over one village, or the tragic deaths of 120 people (at least half of whom were combatants). The exaggerated stories of the day spread became increasingly lurid and triggered widespread panic among Arab villagers throughout the area— which prompted an increasing number to abandon their homes and flee.

An immediate result of the Deir Yassin attack was a retaliatory strike against a Jewish medical convoy of doctors and nurses heading to Hadassah Hospital on Mt Scopus. Typically escorted by the British, the convoys found itself without protection on April 13th, as no British escort showed up. Despite the absence of an escort, The convoy set off without one and as the convoy proceeded, only to be halted by a mine explosion that obstructed their advance. While some vehicles managed to retreat to West Jerusalem, two armored buses and two escort vehicles were left trapped. For five hours, the trapped force was able to fight off the attackers, without any assistance from the British, who refused to help. Eventually, their ammunition ran out, allowing the Arabs to advance on the buses douse them in gasoline, and set them afire. Tragically, 78 individuals, including professors doctors, nurses and patients were all burned alive in the blaze.
 
In the North, the Arab Liberation Army, commanded by Fawzi al- Kawukji, launched a concentrated assault on Mishmar Ha'emek, but was ultimately defeated. Following this setback, the forces had to retreat to Jenin. This defeat destroyed the morale of the Arab villages in the area, leading to a mass exodus of their inhabitants.

In mid-April, the Haganah launched operation Yiftach, whose goal the liberation of the upper Galilee. On April 18, the Palmach took control of Tiberias. By April 21, as the British withdrew from Haifa proper, concentrating their remaining troops in the port area, the Haganah swiftly won the brief battle for the city. By May 10, the Haganah had taken control the Arab sectors of Safed, and by May 16, Akko was captured. On May 13, Jaffa was captured, as well.

On the Jerusalem front, the Palmach successfully seized most of the major British strongholds in the city. However, on May 14, the Etzion bloc succumbed to attackers from the Arab Legion.

The days leading up to independence marked a time of the successful consolidation for the Jewish forces. All of the areas allotted to the Jewish State in the Galilee were firmly under Jewish control, as well as some areas designated for the Arab State. The coastal plain and Jewish Jerusalem were both secure, although the access route to Jerusalem and numerous isolated settlements in the South remained significant concerns.