The ANZUS Security Treaty binds together Australia, New Zealand, and the United States. ANZUS was signed in San Francisco on September 1, 1951, and took effect on April 28, 1952. It remains in force, although it has increasingly come under attack by both Australia and New Zealand since the 1980s and New Zealand has essentially withdrawn from the alliance.
Beginning in the late 1940s the United States abandoned the isolationist impulse that had directed its foreign policy in previous decades to form and maintain a global network of alliances. U.S. policy makers in the cold war were especially interested in opposing the rise of communism. Following the outbreak of the Korean War in 1950, the United States became concerned with constructing a series of regional security arrangements to guard against communist attacks. For Australia and New Zealand, alliances were a necessity because of their need for protection, particularly from Communist China, the Soviet Union, and due to the problems associated with decolonization in Asia and the Pacific. Both countries were also concerned about the return of Japan to sovereign status, and sought a replacement for Great Britain as a dependable security guarantor. The United States offered exactly what both sought.
The ANZUS Treaty stipulates that an armed attack on New Zealand, Australia, or the United States would be dangerous to each signatory’s own peace and safety. Accordingly, each country would act to meet the common danger in step with its constitutional processes. In the early and mid-1950s the United States rejected Australian efforts to move toward more security cooperation such as cooperative and systematic military planning and the designation of national security units that might fall under the ANZUS name and assignment, similar to the North Atlantic Treaty Organization (NATO) model.
After the ANZUS pact was signed, nonsecurity ties between the three countries grew, paralleling the building of their security relations. Commercial, cultural, and other forms of U.S. influence were largely welcomed during the cold war years. The great disparity of size and power generated irritation within Australia and New Zealand, however, and both countries complained about the way they were treated by the United States, although both developed close military cooperation with the United States. Australia, in particular, became a valuable site for U.S. communication and surveillance facilities and naval ship visits.
As the cold war began to wind down in the 1980s, the threat from outside sources lessened. Citizens of the two nations, particularly among members of the labor, began to question the elaborate security ties with the United States. Citizens of New Zealand and Australia challenged ANZUS as more a method for the United States to enlist support for its military agenda than a means of providing security for them.
In 1984 New Zealand banned the entry of U.S. Navy ships into its ports in the belief that the ships were carrying nuclear weapons or were nuclear powered. The United States argued that New Zealand’s action compromised U.S. military operations. Additionally, Americans were offended by the manner in which New Zealand presented its differences with U.S. policy makers.
When President Ronald Reagan announced in 1986 that the United States would decline to abide by the provisions of the unratified Strategic Arms Limitation Treaty (SALT) II that restricted nuclear weapons, New Zealand stated that the United States had not been negotiating in good faith. The United States responded by rescinding its ANZUS-based security obligations toward New Zealand in 1986.
The future of ANZUS is in doubt. New Zealand has shown no indication that it wants to resume the partnership. For Australia, the alliance with the United States has continued to be a foundation of its defense policy.
See also South East Asia Treaty Organization (SEATO).