You do realise their was no sovereign state of Palestine before Palestinians (referred to as Arabs then) were apparently forced to give over their land, and the Arabs in the region of Palestine never had their own State.
There was a Jewish population and by all accounts a large immigrant population of Arabs from surrounding countries after the British started administering it in 1919.
73% of the British Mandate had already been handed over to create an Arab State - Jordan
Of the 27% left over, to split further again for another Arab State and a Jewish State, the majority of land allocated to the Jewish people was the Negev desert!
Ask the 2 million Arabs in Israel, those who were, or descended from, the Arabs who decided to remain in Israel in 1948, if the Jewish people wanted to co exist with them?
Or the Jewish people of 1948 in what is now Jordan, if the Arabs there wanted to co exist with them or why the British Government restricted Jews from settling there.
The British Balfour Declaration endorsed the idea of a Jewish homeland in Palestine, though its borders were not defined. Boundaries for a British Mandate for Palestine were proposed by the World Zionist Organization to the Paris Peace Conferenceof 1919:
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"The fertile plains east of the Jordan, since the earliest Biblical times, have been linked economically and politically with the land west of the Jordan. The country which is now very sparsely populated, in Roman times supported a great population. It could now serve admirably for colonisation on a large scale. A just regard for the economic needs of Palestine and Arabia demands that free access to the Hedjaz Railway throughout its length be accorded both Governments."
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Notwithstanding the wishes of the WZO, the British administration from as early as 1917 treated territory east of the Jordan River, known as Transjordan, separately, and saw it as a separate future state. A formal restriction of the Jewish homeland to west of the Jordan was announced at the Cairo conference in March 1921, and a new article was added to the draft mandate text allowing the British government to administer Transjordan separately. The mandate was approved by the League of Nations in July 1922, and in September 1922 the League approved a memorandum spelling out in detail the exclusion of Transjordan from the Jewish homeland provisions.
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The only formally approved presence of Jews in Transjordan was in the late 1920s. In 1927, Pinchas Rutenberg, founder of the Palestine Electric Company, signed an agreement with the Emir of Transjordan Abdullah I to build a hydroelectric power station on Transjordan territory. Construction of the Naharayim hydroelectric power plant began in 1928. Tel Or was built near the power plant to house the permanent employees and their families. Tel Or was settled in 1930 and was the only Jewish village in Transjordan at the time. Residents also farmed thousands of dunams of land and sold some of the produce at a company workers’ supermarket in Haifa. The town lasted until its depopulation in 1948 during the Arab-Israeli War, when it was overrun by Iraqi and Transjordanian forces and destroyed.