In 1984, Prime Minister David Lange banned nuclear-powered or nuclear-armed ships from using New Zealand ports or entering New Zealand waters. Under the New Zealand Nuclear Free Zone, Disarmament, and Arms Control Act 1987,New Zealand Nuclear Free Zone, Disarmament, and Arms Control Act 1987 territorial sea, land and airspace of New Zealand became nuclear-free zones. This has since remained a part of New Zealand's foreign policy.

The act prohibits "entry into the internal waters of New Zealand 12 nautical miles (22.2 km, statute miles) radius by any ship whose propulsion is wholly or partly dependent on nuclear power" and bans the dumping of radioactive waste into the sea within the nuclear-free zone, as well as prohibiting any New Zealand citizen or resident "to manufacture, acquire, possess, or have any control over any nuclear explosive device."New Zealand Nuclear Free Zone Extension Bill - Green Party The nuclear-free zone Act does not prohibit land-based nuclear power plants, nuclear research facilities, the use of radioactive isotopes, or other land-based nuclear activities. However, no such research facilities or power plants exist currently in New Zealand.

After the Disarmament and Arms Control Act was passed by the Lange-led Labour government, the United States government suspended its ANZUS obligations to New Zealand. The legislation was a milestone in New Zealand's development as a nation and seen as an important act of sovereignty, self-determination, and cultural identity. New Zealand's four-decade anti-nuclear campaign is the only successful movement of its type in the world which resulted in the nation's nuclear-weapon-free zone status being enshrined in legislation.

In 2021, Australia entered into AUKUS pact to get support in building nuclear submarines. In response, New Zealand's prime minister Jacinda Ardern announced that Australia's new submarines will be banned from entering New Zealand's long-standing nuclear-free zone.

Historical background Initial seeds were sown for New Zealand's 1987 nuclear-free zone legislation in the late 1950s with the formation of the local Campaign for Nuclear Disarmament (CND) organisation between 1957 and 1959.Elsie Locke, Peace People: A History of Peace Activities in New Zealand, p. 164 In 1959, responding to rising public concern following the British hydrogen bomb tests in Australia and the Pacific, New Zealand voted in the UN to condemn nuclear testing while the UK, US and France voted against, and Australia abstained. In 1961, CND urged the New Zealand government to declare that it would not acquire or use nuclear weapons and to withdraw from nuclear alliances such as ANZUS. In 1963, the Auckland CND campaign submitted its 'No Bombs South of the Line' petition to the New Zealand parliament with 80,238 signatures calling on the government to sponsor an international conference to discuss establishing a nuclear-free-zone in the southern hemisphere. It was the biggest petition in the nation since the one in 1893 which demanded that women must have the right to vote.

Mururoa atoll, and its sister atoll Fangataufa, in French Polynesia in the southern Pacific Ocean were officially established as a nuclear test site by France on 21 September 1962 and extensive nuclear testing occurred between 1966 and 1996. The first nuclear test, codenamed Aldébaran, was conducted on 2 July 1966 and forty-one atmospheric nuclear tests were conducted at Mururoa between 1966 and 1974.

In March 1976 over 20 anti-nuclear and environmental groups, including Greenpeace and Friends of the Earth, met in Wellington and formed a loose coalition called the Campaign for Non-Nuclear Futures (CNNF). The coalition's mandate was to oppose the introduction of nuclear power and to promote renewable energy alternatives such as wind, wave, solar and geothermal power. They launched Campaign Half Million. CNNF embarked on a national education exercise producing the largest petition against nuclear power in New Zealand's history with 333,087 signatures by October 1976. This represented over 10% of the country's total population of 3 million. At this time, New Zealand's only nuclear reactor was a small sub-critical reactor that had been installed at the School of Engineering of the University of Canterbury in 1962. It had been given by the United States' Atoms for Peace programme and was used for training electrical engineers in nuclear techniques. It was dismantled in 1981.

Regional anti-nuclear sentiment was consolidated in 1985 when eight of the thirteen South Pacific Forum nations signed the South Pacific Nuclear-Weapon-Free Zone Treaty or Treaty of Rarotonga.

Mururoa protests Community inspired anti-nuclear sentiments largely contributed to the New Zealand Labour Party election victory under Norman Kirk in 1972. In June 1973, the International Court of Justice (pursuant to a case launched by Australia and New Zealand) ordered that the French cease atmospheric nuclear testing at Mururoa atoll while the case was being heard by the Court. However, the French ignored this ruling.

Mururoa was the site of numerous protests by various vessels, including the Rainbow Warrior. In a symbolic act of protest the Kirk government sent two of its navy frigates, and , into the test zone area in 1973.Mururoa Nuclear Tests, RNZN protest Veterans - Home A Cabinet Minister (Fraser Colman) was randomly selected to accompany this official New Zealand Government protest fleet. This voyage included a number of local Kiwi peace organisations who had organised an international flotilla of protest yachts that accompanied the frigates into the Mururoa zone. Many of the early NZ peace activists and organisations were enthusiastic young hippies and students, many of whom were involved with the counter-culture and the original opposition to the Vietnam War movements.Elsa Caron, (ed.) 1974, Fri Alert (Caveman Press, Dunedin) The yacht Fri's own story of her protest voyage into the French Bomb Test Zone.

Peace yachts attempting to disrupt the French tests sailed in coordinated protests through the Mururoa exclusion zones between 1972 and 1991. These included the voyage of the first joint Greenpeace-CND campaign in 1972 with David McTaggart, (who co-founded Greenpeace), on the yacht Vega (renamed Greenpeace III). This was followed in 1973 by a flotilla of yachts organised by the Peace Media with protest yachts Fri, Spirit of Peace, the Boy Roel, Magic Isle and the Tanmure.Library Catalogue Search

During numerous voyages to Mururoa atoll the protest yachts Fri, Vegas and Greenpeace were boarded by French commandos and members of their crew assaulted and arrested. In 1973 the Vega was rammed by a French military warship and David McTaggart was severely beaten by French military police. A major change in New Zealand society caused by these Pacific campaigns was the upsurge in pro anti-nuclear sentiments in New Zealand and, as a consequence, the eventual rise of its anti-nuclear policy in 1987.

According to French journalist Luis Gonzales-Mata in Actual magazine 1976, large numbers of Polynesians had been secretly sent on military flights to Paris for treatment for cancer. Tahitian activist Charlie Ching told a nuclear-free Pacific hui in Auckland in 1983 that more than 200 Tahitians had died from radiation-linked illnesses over 5 years. Due to the secrecy of health issues in French Polynesia, these figures remained impossible to confirm.

In August 2006 people of French Polynesia welcomed an official report by the French Government confirming the link between an increase in the cases of thyroid cancer and France's atmospheric nuclear tests in the territory since 1966.

Nuclear-free zone legislation Despite the steady growth of the nuclear-free movement since the 1950s, the early 1980s National Party government was completely against tighter nuclear restrictions and instead sought closer ties with the United States, New Zealand's most powerful ally who possessed the largest nuclear arsenal in the world. Prime Minister Robert Muldoon had lost the support of some of the MPs from his own party over several environmental issues. In particular, maverick National Party Members of Parliament Marilyn Waring and Mike Minogue threatened the slight government majority. In 1984, the opposition New Zealand Labour Party proposed the nuclear-free zone legislation. Muldoon strongly opposed the proposal, fearing it might compromise New Zealand's national security. However, as he failed to secure Marilyn Waring's support on the issue, and as the National Party had a majority of only one, Muldoon decided to call a snap election, the 1984 New Zealand general election, stating that Waring's "feminist anti-nuclear stance" threatened his ability to govern. Muldoon was famously drunk when he announced the election, and ignored warnings from party president Sue Wood that the party organisation was unprepared for a campaign. The National Party lost the election, and the Labour Party formed a new government.Gustafson, Barry, His Way, a biography of Robert Muldoon, Auckland University Press, 2000, , p. 375

According to opinion polls taken before the 1984 election, 30 per cent of New Zealanders supported visits by US warships with a clear majority of 58 per cent opposed, and over 66 per cent of the population lived in locally declared nuclear-free zones. Following the victory of the New Zealand Labour Party in elections in 1984, Prime Minister David Lange barred nuclear-powered or nuclear-armed ships from using New Zealand ports or entering New Zealand waters. Reasons given were the dangers of nuclear weapons, continued nuclear testing in the South Pacific, and opposition to US President Ronald Reagan's policy of aggressively confronting the Soviet Union. Given that the United States Navy refused to confirm or deny the presence of nuclear weapons aboard ships, these laws essentially refused access to New Zealand ports for all United States Navy ships. In February 1985, a port-visit request by the United States for the USS Buchanan was refused by the New Zealand government on the basis that the Buchanan was capable of launching nuclear depth bombs. This refusal was viewed by the New Zealand public as an important statement of national sovereignty, illustrating a refusal to relax its anti-nuclear stance even at the behest of its more powerful allies. An opinion poll commissioned by the 1986 Defence Committee of Enquiry confirmed that 92 per cent now opposed nuclear weapons in New Zealand and 69 per cent opposed warship visits; 92 per cent wanted New Zealand to promote nuclear disarmament through the UN, while 88 per cent supported the promotion of nuclear-free zones.