Mention of the Balfour Declaration in the news today, 106 years later, is pertinent However, suggesting that Britain left Palestine in 1948 with the Mandate unresolved, which after World War II was the eventual result of the Balfour Declaration, and omitting any mention of cause for Britain leaving, was a smoke screen. It did not happen in a vacuum. Far from it.
Britain was responsible for the administration of Mandated Palestine as agreed upon by the UN November 1947. The UN had appointed Count Bernadette to be the Mandate's chief negotiator, shortly after the leadership of the Jewish Liberation Army had declared Israel to be a nation May 1948 - without there as yet being agreed upon established boundaries.
After the assassination of the Mandate's chief negotiator by the Stern terrorist gang, September 1948, it became abundantly clear to the administrator of the Mandate, Britain, the criminal extents to which the brand new self-declared state of Israel was willing to go to prevent further negotiation of the Mandate boundaries.
The fact is that neither Palestinians nor Israelis were happy with the initial Mandate plan. Thus the appointing of Swedish Count Bernadette, assassinated in September by the same terrorist gangs that had committed the massacre in Deir Yassin, in April, a month before the declaration of Israel as a nation without agreed upon boundaries.
Leading up to the massacre there had been many people in Palestinian villages killed, for no reason and without cause, after the Jewish Liberation Army had given Palestinians the ultimatum to leave or be killed, prior to declaring Israel a nation approximately a month later. After Deir Yassin Palestinians realized the threats of the Jewish Liberation Army leadership telling them to leave or be killed, were promises. The first wave of Palestinian refugees started leaving the area that was as yet an unnegotiated first effort to establish boundaries for two states in Palestine - one Jewish and one Arab.
In the most simple of terms there was apparently neither desire nor intention of the new Jewish state to agree to any Mandate. Britain did not simply give up and go home in 1948, without reason, leaving the Mandate unresolved at that time.