ANZUS Treaty

The ANZUS Treaty is a 1951 security pact that binds Australia, New Zealand, and the United States. The acronym "ANZUS" is derived directly from the first letters of these three nations.

The treaty requires the signatory nations to cooperate on military defense in the Pacific Ocean area. Under Article IV, an armed attack on any of the parties would trigger mutual consultation and a commitment to act to meet the common danger.

The defense obligations between the United States and Australia remain fully intact, but the trilateral pact was severely strained in 1986. The US suspended its security commitments to New Zealand after NZ implemented a nuclear-free policy that banned US nuclear-armed ships from its ports.

The treaty was signed on September 1, 1951, and entered into force in 1952. It was created in the early context of the Cold War to formally align the Pacific nations and establish regional security following the outbreak of the Korean War.