“His Majesty's Government view with favour the establishment in Palestine of a national home for the Jewish people, and will use their best endeavours to facilitate the achievement of this object, it being clearly understood that nothing shall be done which may prejudice the civil and religious rights of existing non-Jewish communities in Palestine, or the rights and political status enjoyed by Jews in any other country.”
There are two important things to keep in mind when it comes to the Balfour Declaration: (1) in 1917, Palestine was not yet under British rule; thus, the British had no actual power to assign it to anyone, and (2) by the time the British were given administrative powers over Palestine, they’d already changed their tune in favor of the Arab aspirations. You also have to understand that the Balfour Declaration never specified the exact nature of this “national home for the Jewish people,” and, as such, the British felt that this promise did not actually contradict the earlier promise they had made to the Arabs in 1916 regarding a unified Arab state in Greater Syria.
The causes for the Balfour Declaration are subject to speculation. Some historians believe the British wanted to reward Chaim Weizmann, one of the most active proponents for a Jewish state, for producing acetone, which was critical to the British war effort during World War I. Others believe the British were desperate for the Americans to enter World War I, and because they held the antisemitic view that Jews had a great deal of power over the American government, they thought that in rewarding the Jews, the Jews would reward them. Others claim Lord Balfour was a Christian Zionist (not to be confused with a Christian who is a Zionist) and he felt that the returning of the Jews to the Land of Israel would hasten the Second Coming of Jesus. Others think the British “embraced” Zionism because they felt that it would justify their colonization of Palestine over the French colonization of Palestine, as the French were also vying for control of that strip of land.
Fundamentally, before the British even set foot in Palestine, they had made contradictory promises of sovereignty to Jews, Arabs, and other Middle Eastern minorities.
But, by the time that the British actually were in Palestine, they actively did everything they possibly could to appease the Arabs, actually working to prevent the establishment of a Jewish state.
Had a Jewish state not become a reality in spite of the British, the Balfour Declaration would have long been forgotten, just like the unfulfilled promises the British made to the Assyrians and Kurds.
The fact of the matter is that virtually every border in the Middle East was carved up by the British and French, yet only the Jewish state is delegitimized on that basis. In fact, some countries were invented by the British entirely. For example, the British aided in the creation of Saudi Arabia by funding and supporting the Al Saud family, which, with their help, came to dominate a large chunk of the Arabian Peninsula. The British quite literally invented Iraq when they created the Mandate of Iraq in 1921 in part of what had long been known as other regions, including Assyria, Mesopotamia, and Babylonia. And, of course, the British created Jordan when they handed an enormous piece of the Mandate of Palestine over to the Hashemites in 1922. The Hashemites are from Arabia, not Transjordan.
So you can do the hack thing of trying to delegitimize the State of Israel as a British colonial project by decontextualising one single paragraph-long, non-binding statement (Balfour Declaration) and ignore everything that happened before and since full, but you’re on a hiding to nothing.
The fact of the matter is that by the time the British actually occupied the territory that now encompasses the State of Israel and the Palestinian Territories, they actively worked with the Arabs against the establishment of a sovereign Jewish state.
Anyone familiar with the complicated history of the conflict beyond the same tired propaganda talking points knows this.
Try harder.