Australia-New Zealand-United States Security Treaty

(ANZUS)

   The ANZUS was a mutual defense security treaty agreed upon on 1 September 1951 and put into effect on 29 April 1952. It stated that an attack on any one of the countries—Australia, New Zealand, or the United States—would be regarded as an attack on them all. The treaty reflected both the close cooperation between the three nations during World War II and the impact of the Cold War in the Pacific following the communist takeover in China. However, the treaty came under strain in 1985 when New Zealand objected to nuclear testing in the Pacific by the United States and refused to allow nuclear vessels into its ports. The United States abrogated the treaty with regard to New Zealand in 1986, but New Zealand has not formally withdrawn from the agreement. Both Australia and New Zealand supported the United States in the war against the Taliban in Afghanistan following the 1991 attack on the World Trade Center in New York City.