The ANZUS treaty, signed in San Francisco in September 1951, was one of several early Cold War alliances. ANZUS formed a military alliance between the United States, Australia and New Zealand, declaring that an attack on one would be considered an attack on all three:
“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,
Noting that the United States already has arrangements pursuant to which its armed forces are stationed in the Philippines, and has armed forces and administrative responsibilities in the Ryukyus [Japan]…
Recognising 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 defence for the preservation of peace and security pending the development of a more comprehensive system of regional security in the Pacific Area, therefore declare and agree as follows:
Article I. The Parties undertake, as set forth in the Charter of the United Nations, to settle any international disputes in which they may be involved by peaceful means, in such a manner that international peace and security and justice are not endangered and to refrain in their international relations from the threat or use of force in any manner inconsistent with the purposes of the United Nations.
Article II. In order more effectively to achieve the objective of this Treaty, the Parties separately and jointly by means of continuous and effective self-help and mutual aid, will maintain and develop their individual and collective capacity to resist armed attack.
Article III. The Parties will consult together whenever in the opinion of any of them the territorial integrity, political independence or security of any of the Parties is threatened in the Pacific.
Article IV. Each Party recognises that an armed attack in the Pacific Area on any of the Parties would be dangerous to its own peace and safety and declares that it would act to meet the common danger in accordance with its constitutional processes.
Any such armed attack and all measures taken as a result thereof shall be immediately reported to the Security Council of the United Nations…
Article V. For the purpose of Article IV, an armed attack on any of the Parties is deemed to include an armed attack on the metropolitan territory of any of the Parties, or on the island territories under its jurisdiction in the Pacific or on its armed forces, public vessels or aircraft in the Pacific…
Article X. This Treaty shall remain in force indefinitely…”