Does FN=UN? That's not quite how it happened. By the time the UN put forward its partition plan there were already quite a lot of Jews in Palestine who owned quite a lot of land in their own right. They had other purchased it from locals, from former Ottoman landlords, or as I understand it in a limited number of grants before 1918 from the Sultan himself. By the end of World War II many more were flooding into Palestine as refugees fleeing the holocaust, but were landless.

The UN, at the request of the UK, which was the mandatory power responsible for Palestine, was asked to come up with a partition plan to resolve the near-constant insurgency that Britain had been dealing with between 1936-47. Britain had decided as early as the 1936 Peel commission that their original plan for some sort of federal one state solution had failed because, in their new view, a Jewish national home in Palestine, as described by the Balfour declaration, was incompatible with that declaration's guarantee that "nothing shall be done which may prejudice the civil and religious rights of existing non-Jewish communities in Palestine." As such Britain advocated partition, but met with the 1936-9 uprising, which they put down quite brutally.

World War II gave something of a reprieve from similar Jewish uprisings, but ultimately fighting resumed, Britain handed the issue off to the UN, which recommended partition (the UNSCOP report,) and the neighboring Arab states (who were negotiating on behalf of Palestine's basically leaderless, disorganized, unrepresented Arabs) rejected the plan and UN resolution 181.

The result was the '47 "civil war," and immediately following Britain's withdrawal the '48 war, where Israel was created not by the UN, but on a basis determined by the armistice lines between the newly declared state of Israel and the Arab powers.

edit: just to emphasize the point to make myself more clear. The UN had a partition plan, but as I've explained it was never carried out because it was rejected by the Arab parties. As a result Israel and Palestine were partitioned by the fighting in '48, not the UN.