Charter of the United Nations; June 26, 1945

https://avalon.law.yale.edu/20th_century/unchart.asp

WE THE PEOPLES OF THE UNITED NATIONS DETERMINED to save succeeding generations from the scourge of war, which twice in our lifetime has brought untold sorrow to mankind, and to reaffirm faith in fundamental human rights, in the dignity and worth of the human person, in the equal rights of men and women and of nations large and small, and to establish conditions under which justice and respect for the obligations arising from treaties and other sources of international law can be maintained, and to promote social progress and better standards of life in larger freedom, AND FOR THESE ENDS to practice tolerance and live together in peace with one another as good neighbours, and to unite our strength to maintain international peace and security, and to ensure, by the acceptance of principles and the institution of methods, that armed force shall not be used, save in the common interest, and to employ international machinery for the promotion of the economic and social advancement of all peoples, HAVE RESOLVED TO COMBINE OUR EFFORTS TO ACCOMPLISH THESE AIMS Accordingly, our respective Governments, through representatives assembled in the city of San Francisco, who have exhibited their full powers found to be in good and due form, have agreed to the present Charter of the United Nations and do hereby establish an international organization to be known as the United Nations.

Article 76 The basic objectives of the trusteeship system, in accordance with the Purposes of the United Nations laid down in Article 1 of the present Charter, shall be:

a. to further international peace and security;

b. to promote the political, economic, social, and educational advancement of the inhabitants of the trust territories, and their progressive development towards self-government or independence as may be appropriate to the particular circumstances of each territory and its peoples and the freely expressed wishes of the peoples concerned, and as may be provided by the terms of each trusteeship agreement;

c. to encourage respect for human rights and for fundamental freedoms for all without distinction as to race, sex, language, or religion, and to encourage recognition of the interdependence of the peoples of the world; and

d. to ensure equal treatment in social, economic, and commercial matters for all Members of the United Nations and their nationals, and also equal treatment for the latter in the administration of justice, without prejudice to the attainment of the foregoing objectives and subject to the provisions of Article 80.

Security Treaty Between the United States, Australia, and New Zealand (ANZUS); September 1, 1951(1)

https://avalon.law.yale.edu/20th_century/usmu002.asp

The Parties to this Treaty,

Reaffirming their faith in the purposes and principles of the Charter of the United Nations and their desire to live in peace with all peoples and all Governments, and desiring to strengthen the fabric of peace in the Pacific Area,

Recognizing that Australia and New Zealand as members of the British Commonwealth of Nations have military obligations outside as well as within the Pacific Area,

Desiring to declare publicly and formally their sense of unity, so that no potential aggressor could be under the illusion that any of them stand alone in the Pacific Area, and

Desiring further to coordinate their efforts for collective defense for the preservation of peace and security pending the development of a more comprehensive system of regional security in the Pacific Area,

There is a lot to read here. For the most part the UN deals with international disputes but it does say specifically they reaffirm faith in fundamental human rights, in the dignity and worth of the human person, in the equal rights of men and women and of nations large and small. If it can be shown the Australian government is being backmailed or bought by a foreign entity to enslave its own people, The UN and every nation signed on UN Charter has an obligation to react.