ANZUS

The Australia, New Zealand, United States Security Treaty (ANZUS or ANZUS Treaty) is a collective security agreement between Australia, New Zealand, and the United States that was signed in 1951, and from which New Zealand has been partially suspended since 1986. It firstly recommits the parties to the purposes of the United Nations, prohibiting the use of force or threats except in self-defence. The following provisions require the parties to maintain their "capacity to resist armed attack", consult with each other on security matters in the Pacific and declare that an armed attack on any of the parties "would be dangerous to [each signatory's] peace and safety" and that each signatory "would act to meet the common danger in accordance with its constitutional processes". It also provides for a council of the signatories foreign ministers, in which the implementation of the treaty can be discussed.

The treaty was one of a series that the United States formed in the 1949–1955 era as part of its collective response to the threat of communism during the Cold War. New Zealand was suspended from ANZUS in 1986 as it initiated a nuclear-free zone in its territorial waters. In late 2012, the United States lifted a 26-year-old ban on visits by New Zealand warships to US Department of Defense and US Coast Guard bases around the world. New Zealand maintains a nuclear-free zone as part of its foreign policy and is partially suspended from ANZUS, as the United States maintains an ambiguous policy whether or not the warships carry nuclear weapons and operates numerous nuclear-powered aircraft carriers and submarines; however New Zealand resumed key areas of the ANZUS treaty in 2007.