Plan Dalet - Execution

Execution

The first operation, named Nachshon, consisted of lifting the blockade on 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 April and 20 April. The operation was successful, and enough foodstuffs to last 2 months were trucked into to Jerusalem for distribution to the Jewish population. The success of the operation was assisted by the death of Al-Hassayni in combat. During this time, and independently of Haganah or the framework of Plan Dalet, irregular troops from Irgun and Lehi formations massacred a 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 Palestinian population.

At the same time, April 4–14, the first large-scale operation of the Arab Liberation Army ended in a "débâcle", 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. Palestinian society was shaken. Tiberias, Haifa, Safed, Beisan, Jaffa and Acre fell, resulting in the flight of more than 250,000 Palestinians.

The British had, at that time, essentially withdrawn their troops. The situation pushed the leaders of the neighboring Arab states to intervene, but their preparation was not finalised, and they could not assemble sufficient forces to turn the tide of the war. Many Palestinian hopes lay with the Arab Legion of Transjordan's monarch, King Abdullah I, but he had no intention of creating a Palestinian-run state, since he hoped to annex as much of the territory of the British Mandate of Palestine as he could.

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.