Balfour Declaration

The story I have heard, is that Zionist activists (esp. Chaim Weizmann) made use of the conspiracy theories about Jews controlling the world—which many British officials believed at the time—to make themselves seem more influential than they really were. The war front was barely holding together; British leaders were desperate for any advantage, and were thus more susceptible to such tactics. (Also, some British officials were committed Zionists for religious reasons, and pushed the cause internally with whatever arguments were available to them.)

This was the British Empire with full momentum. I expect the no-records-exist briefings started with explaining who the Jews were, and how installing them in this part of the Ottoman Empire would disrupt the ability of the Arabs to reorganise themselves for generations; securing British hegemony.

There is a reason that the Chinese ended up with the paranoid and insular government that they have - everything else got torn apart by the West. If you look in Africa, the Middle East or the Americas you can see the tattered shreds of former empires that didn't take the British threat (et, al - Europeans really) seriously enough. They were really good at dismantling things.