The Australia, New Zealand, United States Security Treaty (ANZUS or ANZUS Treaty) is the military alliance which bound Australia, New Zealand and the United States to co-operate on defense matters in the Pacific Ocean area, though today the treaty is understood to relate to attacks in any area. Following a dispute in 1985 over visiting rights for nuclear-armed or nuclear-powered ships of the US Navy in New Zealand ports, the treaty now applies only between United States and Australia, and Australia and New Zealand.
The genesis of the treaty came about following the close co-operation of the United States, Australia and New Zealand during World War II, during which time Australia had come perilously close to defeat by Japan. Post-war, the United States was eager to normalize relations with Japan, particularly as the Korean War was still raging a short distance from Japan and the Cold War was threatening to become a full scale war. Australia and New Zealand in particular were extremely reluctant to finalize a peace treaty with Japan which would allow for re-armament. Both countries relented only when an Australian and New Zealand proposal for a three-way security treaty was accepted by the United States.
The resulting treaty was concluded at San Francisco on September 1, 1951, and entered into force on April 29, 1952. The treaty bound the signatories to recognize that an armed attack in the Pacific area on any of them would endanger the peace and safety of the others. It committed them to consult in the event of a threat and, in the event of attack, to meet the common danger in accordance with their respective constitutional processes. The three nations also pledged to maintain and develop individual and collective capabilities to resist attack.
In 1985, the nature of the ANZUS alliance changed significantly – the government of New Zealand refused access to its ports by nuclear-weapons-capable and nuclear-powered ships of the U.S. Navy, and following the experience of nuclear testing at Maralinga and unwilling to expose Australia to the risk of a nuclear attack from the Soviet Union, Australian Prime Minister Bob Hawke refused to assist the United States in the development of the Peacekeeper intercontinental ballistic missile. The United States suspended defense obligations to New Zealand, while the US was more forgiving of Australia after NATO countries showed little interest in a similar stance against missiles such as the Pershing.
Annual bilateral meetings between the U.S. Secretary of State and the Australian Foreign Minister replaced annual meetings of the ANZUS Council of Foreign Ministers. The first bilateral meeting was held in Canberra in 1985. At the second, in San Francisco in 1986, the United States and Australia announced that the United States was suspending its treaty security obligations to New Zealand pending the restoration of port access. Subsequent bilateral Australia-U.S. Ministerial (AUSMIN) meetings have alternated between Australia and the United States. The 12th AUSMIN meeting took place in Sydney in July 1998.
The U.S.-Australia alliance under the ANZUS Treaty remains in full force. Heads of defense of one or both nations often have joined the annual ministerial meetings, which are supplemented by consultations between the U.S. Commander in Chief Pacific and the Australian Chief of Defense Force. There also are regular civilian and military consultations between the two governments at lower levels.
Unlike NATO, ANZUS has no integrated defense structure or dedicated forces. However, in fulfillment of ANZUS obligations, Australia and the United States conduct a variety of joint activities. These include military exercises ranging from naval and landing exercises at the task-group level to battalion-level special forces training, assigning officers to each other's armed services, and standardizing, where possible, equipment and operational doctrine. The two countries also operate several joint defense facilities in Australia, mainly for signals intelligence gathering.
Whilst Australia has fought alongside the United States since the treaty signing including the Korean War, Vietnam War, the Gulf War, and elsewhere, the ANZUS treaty's provisions for assistance when a member nation comes under threat were officially invoked for the first time by Australia after the September 11, 2001 terrorist attacks. Australia is also a contributor to the National Missile Defense system.  (http://usembassy-australia.state.gov/ausmin/2004/missile-defense.html)  (http://www.foreignminister.gov.au/releases/2003/fa151_03.html)
New Zealand also fought alongside the United States in the Korea and Vietnam, and supplied logistical support for the Gulf War, peace-keeping forces in Afghanistan and engineers in the Iraq war. However, an opinion poll in New Zealand in 2001  (http://www.greenleft.org.au/back/1991/15/15p18b.htm) showed 54% of those sampled preferred to let the treaty lapse rather than accept visits again by nuclear-armed/powered vessels.
The alliance engenders some political controversy in Australia. Particularly after Australian involvement in the 2003 war on Iraq, some quarters of Australian society have called for a re-evaluation of the relationship between the two nations. Nonetheless the alliance enjoyed broad support during the Cold War  (http://assda.anu.edu.au/polls/M0004.html) and continues to enjoy broad support in Australia.  (http://www.australianpolitics.com/foreign/anzus/01-06-30gnehm.shtml)  (http://www.smh.com.au/articles/2004/03/29/1080544419833.html?oneclick=true) One commentator in Australia has argued that the treaty should be re-negotiated in the context of terrorism, the modern role of the United Nations and as a purely US-Australian alliance.  (http://www.onlineopinion.com.au/view.asp?article=2140)
- Text of the ANZUS Treaty (http://www.austlii.edu.au/au/other/dfat/treaties/1952/2.html)
- Australia and the ANZUS Crisis - chronicles the near-death experience of ANZUS in 1985 (http://www.make-believe.org/essays/thesis.html)
- Will New Zealand ever rejoin ANZUS? (http://www.cis.org.au/policy/spr03/polspr03-5.htm)