and in attempting to counter it, its editor-at-large has written
Never mind the League of Nations never designated the whole region from the Jordan river to the sea for a Jewish homeland, never mind that Trans-Jordan was never included in the Palestinian mandate.
Is that a statement of truth?
Well, what is written in the Mandate for Palestine?
In the territories lying between the Jordan and the eastern boundary of Palestine as ultimately determined, the Mandatory shall be entitled, with the consent of the Council of the League of Nations, to postpone or withhold application of such provisions of this mandate as he may consider inapplicable to the existing local conditions
Even a simple-minded human would understand that, at the very least, the region designated for a Jewish homeland had to be from the sea to the Jordan River.
What was in dispute was the area from the Jordan River eastward. And that eastern boundary was not yet determined in 1922.
The Mandatory shall be responsible for seeing that no Palestine territory shall be ceded or leased to, or in any way placed under the control of the Government of any foreign Power.
So, all the other partition suggestions could not have been legal if the League of Nations hadn't somehow acquiesced to them and the 1939 White Paper was not so authorized. In fact, appeals were made to the Mandates Commission in Geneva that summer to deny the British their whittling away of the territory of the Jewish Homeland but the outbreak of World War II thwarted that process.
And the administration angle?
Even Wikipedia informs all that
The Emirate of Transjordan...was a British protectorate established in April 1921...The territory was officially under the British Mandate for Palestine but had a fully autonomous governing system from Mandatory Palestine. In 1946, the Emirate became an independent state.
Never trust MondoWeiss.