P F Tinmore, et al,
I think you have the question wrong.
So, who has the authority to "adjust" the borders of, or within, another country?
(COMMENT)
To be relevant, the question should be:
• Who has the authority to "adjust" the borders of, or within, "territories to which the Mandate for Palestine applies?"
The relevant understanding comes not from merely reading some wording you have stumbled upon, but in actually being able to understand it both then (late 1940's) and now (more than seven decades after the UN Charter). In coming to this deeper understanding, you must reject the patrimonial understanding of territory (as a kind of property) that and moving on in favor of understanding the legitimate political authority --- one in the framework of "popular sovereignty." AND --- in doing so, answer two 21st Century questions: the question of
• What territory is , or what territorial rights involve? and
• What are the conditions under which some some entity has territorial rights?
But in answering these questions, one must be prepared to deal with the dissenting antagonists which fail to accept the contemporary theory as applied today.
√ The Covenant of the League of Nations, to
entrust to a Mandatory selected by the said Powers the administration of the territory of Palestine, which formerly belonged to the Turkish Empire,
within such boundaries as may be fixed by them.
√ On its arrival in Palestine the Commission shall proceed to carry out measures for the establishment of the frontiers of the Arab and Jewish States and the City of Jerusalem in accordance with the general lines of the recommendations of the General Assembly on the partition of Palestine. Nevertheless, the boundaries as described in Part II of this Plan are to be modified in such a way that village areas as a rule will not be divided by state boundaries unless pressing reasons make that necessary.
In the establishment of a relatively new state (Israel), political and terrorist opposition seeking to oppose the establishment of the Jewish National Home tend to seek the source of its legitimacy within the framework of international law either in the territorialist conception, whereby it claims that the Arab Palestinians are somehow entitled to come to independence within a particular and accepted territorial that they have determined is their sovereign territory, as opposed to the true holder of the rights and title to the territory --- with the authority to determine the future of that being in the hands of Allied Powers. The Jewish Immigrants, at the encouragement of the Allied Powers, and as a consequence of the exercise of self-determination, acting cooperatively with the Allied Powers, focused upon a central theme behind the Mandate --- that being the .
The principle of self-determination has risen in importance to become one of the key objectives: "the reconstituting their national home in that country."
In addressing these issues of territory, one must consider the political and legal concepts of modern international law; as well as, the ability to distinguish between the legal right to self-determination (Israel) versus the mere political expression of the doctrine (Arab Palestinians).
Most Respectfully,
R