"The establishment of the mandate was never by lawful authority, only the result of power."
.,,.
How so, Richard? It was established at the end of WW1 by the League of Nations, after General Allenby had captured the territory from the Turks, prior to which it had for several hundred years been part of the Ottoman Empire. After that, even before the League came into being, the British were regarded as being responsible for it, whence the Balfour Declaration of 1917 in response to a request from Weizmann after he had expressed desire for his people, rather than himself, to be rewarded for his contributions to the Allied victories {see Chaim Weizmann in Wikipedia}. The staying on of the British after the League was dissolved led to all sorts of complications which need not be gone into here, leading up to the declaration of Israeli statehood in 1948; when another narrative takes over as we all know ad nauseam from googol threads. Arab residents who had remained there were, & remain, full citizens of Israel. Try googling Arab [or "Palestinian"] Members Of Knesset, for instance.

Richard has to a considerable extent got hold of the wrong end of some stick it seems to me.

~M~