Under the Equator, But Not the Umbrella: New Zealand’s Acceptable Lack of American Nuclear Protection

By Megan Rohn (PO ’18)

In 1951, Australia, New Zealand and the US signed the Australia New Zealand United States Security Treaty (ANZUS), a military alliance and collective security agreement between the three nations.1 Included in this treaty was the agreement that Australia and New Zealand would not pursue nuclear weapons, in exchange for being under the US nuclear umbrella of extended deterrence. However, shortly thereafter in 1984, the Nuclear-Free New Zealand movement swept the nation, and New Zealand became a nuclear-free zone, resulting in it’s suspension from the Treaty in 1986. I learned this from Greg Presland, a politician and my host father in New Zealand, who was very involved in maintaining the movement in the 1980’s.

To this day, New Zealand remains outside of the US nuclear umbrella of extended deterrence.2 Moreover, US warships are not allowed into New Zealand ports because the United States will not declare whether or not it’s military ships carry nuclear weapons,3 but relations have thawed between the two nations and portions of the treaty were resumed in 2007 when the United States allowed New Zealand warships into American ports as a show of good faith.4

To that end, this paper will explore how, if at all, New Zealand’s exclusion from American extended nuclear deterrence affects their approach to international security. This may seem to be an America-centric inquiry because it assumes that other nations’ foreign relations are determined by their relationship to America. However, this assumption is not entirely flawed because in general, America is considered to be the global hegemon, both economically and militarily. Therefore, a country’s relationship with the US can have a significant effect on that country’s actions on the international stage, meaning that the question regarding New Zealand’s international security approach still bears asking.

Upon further investigation, it appears that New Zealand left the United States nuclear umbrella because they decided to be more dedicated to keeping nuclear material out of their country than they were to having a nuclear protector. Implied in this dedication is the fact that New Zealand is not under any imminent nuclear threats from which it would need protection. Given New Zealand’s location, size, and historical position on the international stage, their exclusion from America’s extended nuclear deterrence umbrella has given them greater autonomy in foreign policy without creating a significant national security risk.5

This paper will start by defining some basic terms regarding nuclear weapons. Next, it will present six possible explanations as to why New Zealand does not see the need for nuclear weapons, framed with regard to Scott Sagan’s piece, “Why Do States Build Nuclear Weapons?”6 Then, the paper will address some similarities and differences between New Zealand, Indian, and Australian nuclear policies. It will conclude by explaining that, given New Zealand’s location, demographics, political history, and international relationships, the country decided to forego nuclear protection in favor of moral opposition and autonomous foreign policy.

According to nuclear theorist Kenneth Waltz, nuclear deterrence is a defense strategy whereby two nuclear armed states will never attack each other because the guaranteed losses (e.g. retaliation, environmental damage) outweigh the potential gains (e.g. victory, territory).7 Moreover, extended nuclear deterrence is a defensive strategy wherein Country A, such as the United States, uses its own nuclear arsenal to prevent, or deter, Country B from attacking Country C,8 such as New Zealand. Threat credibility is the degree to which a country’s nuclear posturing, or “threat,” is perceived as convincing, or “credible,” by the rest of the international community.9 The ANZUS Treaty placed Australia and New Zealand under American extended nuclear deterrence, or more colloquially, under the “American nuclear deterrence umbrella,” meaning that they believed American nuclear threat credibility was high.

This paper argues that New Zealand’s subsequent absence from the American nuclear deterrence umbrella has impacted New Zealand foreign policy in a counterintuitive yet positive way. This absence has increased New Zealand’s foreign policy autonomy because they no longer have to accept unwanted potential American nuclear weapons in their ports. Taking such a hardline stance against the United States is a costly signal, even for large or nuclear-armed states. Thus, a statement like this coming from New Zealand is all the more impressive, and speaks to the resilience of the citizens and politicians alike, as well as their commitment to moral priorities and popular opinion over strategic political maneuvers. That said, the decision to leave ANZUS and ban nuclear weapons was made much more feasible by the fact that New Zealand is not the target of many nuclear threats.

The “Autonomy Through Opposition” theory posits that New Zealand left the umbrella because it felt safe enough that it could sacrifice that protection in order to have more autonomous foreign policy.10 This theory provides an excellent frame for my paper and supports my conclusion that leaving the umbrella probably has not affected New Zealand, given their preferential yet inconsequential standing on the international stage. New Zealand may have left ANZUS and become nuclear-free because they wanted “autonomy through opposition.” This indicates that New Zealand’s perceived threat level was very low, because they didn’t feel the need to compromise their values merely for the sake of nuclear protection.11 I have chosen the following six factors as evidence to support this theory.


Contributing Factors to New Zealand’s Lack of Need for Nuclear Weapons:

First, New Zealand is in a relatively stable region and lacks any significant foreign enemies or adversaries, for several historical, geographical, and cultural reasons. According to nuclear proliferation theorist Scott Sagan, one of the three reasons that a state might pursue nuclear weapons is to ensure their own national security,12 but New Zealand’s national security has not been in enough imminent danger in recent years to warrant such a pursuit. New Zealand is not an American enemy, so it is unlikely that the United States or its allies would attack them. Also, New Zealand is comprised of primarily white citizens and it is part of the Commonwealth of the United Kingdom, meaning they will likely not be subject to racism and they have an amicable relationship with their former colonial ruler. Moreover, New Zealand has no nuclear weapons and is small and far away from every other country besides Australia, so it is unlikely to be attacked by the West and unlikely to be seen as a threat. Also, New Zealand was colonized very recently (1840)13 and does not have a history of being an abusive imperial power, which further minimizes their possibility of having external enemies. Although the country still struggles with internal strife between indigenous Maori and colonist-descended Pakeha, it is unlikely to have international foes.

In addition to New Zealand’s own positive international reputation, their country is not located in an unstable region like the Middle East, which has a history of unrest between neighbors. New Zealand is also a first world country, meaning that stability is already relatively high there. Therefore, New Zealand does not necessarily need deterrence because it is not in imminent danger of war like the entire Middle East is. Moreover, New Zealand is not surrounded by enemies like Iran and Israel are, so it does not need to try and alter the regional power balance by obtaining nuclear weapons or protection. Additionally, New Zealand is not a revisionist state like Iran and North Korea are, so they have no need for deterrence or nuclear weapons with which to realize their revisionist ambitions.

Second, New Zealand has a historically passive foreign policy, which contributes to their lack of nuclear ambitions. Sagan proposes another reason why states might seek nuclear weapons: to meet international norms and gain prestige.14 However, international norms are not New Zealand’s top priority, because New Zealand politics are highly inward-focused. New Zealand depends heavily on Australia, the UK, China, and America for trade.15 However, the New Zealand government does not have a revisionist or invasive foreign policy agenda like that of America, and as such, New Zealand does not require nuclear weapons to enforce such an agenda. Under the current prime minister, Jacinda Ardern, New Zealand’s two main foreign policy objectives are to stop foreign land speculation and decrease immigration (due to the housing crisis), which I learned while campaigning for Jacinda last year. If anything, their lack of nuclear weapons or extended deterrence has made New Zealand’s foreign policy more compliant due to their apparent lack of “protection.” However, this is not necessarily true either because, as previously stated, New Zealand does not have any significant adversaries.

Deputy Prime Minister Winston Peters called for a “seismic change” in New Zealand foreign diplomacy in 200816 because felt that New Zealand had an insufficient presence on the world stage. He intended to increase New Zealand’s number of foreign diplomats abroad by 50%, but this policy was cancelled when the opposing party was voted into government during the following election.17 This further supports the idea that New Zealand does not have any significant adversaries abroad, because they themselves admit that New Zealand is not the most significant player on the international stage. This is not to say that New Zealand does not have a significant impact on global affairs. Rather, the nation’s two main political parties (one liberal and one conservative) tend to agree on foreign policy, so it is never at the top of their agenda. Specifically, the left and right wing both agree that the lions share of New Zealand foreign policy should be dedicated to nuclear disarmament, humanitarian aid, and free trade, meaning that most political conflicts are centered on domestic issues like housing and healthcare.

Third, New Zealand’s domestic policy agenda is hostile to nuclear weapons development. Sagan’s third explanation for why a state would pursue nuclear weapons is that their domestic political agenda calls for such weapons.18 However, New Zealand’s domestic policy has been decidedly anti-nuclear since Prime Minister David Lange signed the Nuclear Free New Zealand movement into law and eliminated New Zealand from ANZUS in 1986, as Greg Presland explained to me. This eliminates Sagan’s third possible explanation.

New Zealand’s two dominant political parties are the Labour Party, which equates to the Democratic Party America, and the National Party, which equates to the Republican Party in America. Historically, the Labour Party has a Liberal perspective and prioritizes supporting the United Nations, humanitarian aid, and human rights. Conversely, the National Party has de-emphasized these institutions and focused on security from a Realist perspective.19 Prime Minister Lange belonged to the Labour Party and, despite other differences, both parties have supported Labour’s decision to be anti-nuclear since 1986. As such, neither party has been revisionist or landed New Zealand in any threatening circumstances in which they have come under nuclear threat. For instance, New Zealand did not initiate the invasion of another country like Iraq because of potential nuclear weapons, nor have they referred to a rising nuclear power like North Korea as a member of the “axis of evil”.20 New Zealand has contributed troops to many wars, but neither domestic political party has started any wars itself. This bipartisan agreement, rare in America, leaves New Zealand with no nuclear enemies.

Fourth, New Zealand may reap certain benefits by being nonaligned with the US. America has several enemies, and has a reputation for being the “world police”21 and exerting too much influence in too many places, including two never-ending wars in Iraq and Afghanistan. New Zealand may benefit from not being in the American deterrence umbrella. This is the case because it means New Zealand is not explicitly allied with the US, meaning that Russia and North Korea might hold less animosity toward New Zealand than they would if New Zealand were explicitly allied with the US. This is an important consideration because North Korea is closer to New Zealand than it is to America, so it might be in New Zealand’s interest to not be squarely on America’s “side.” That is, New Zealand’s nonaligned position could afford them leverage to show North Korea that New Zealand is not merely another American puppet.

Fifth, exclusion from American extended deterrence does not “hurt” New Zealand’s relationship with the hegemonic US. Much like America, New Zealand wants to help with the South China Sea dispute because half of their trade goes through there.22 New Zealand also values their good relationships with China and Japan and Australia, just like the US does. This means that New Zealand and the US have many common allies and trading partners, suggesting that New Zealand will continue to have a positive relationship with the United States. Furthermore, trade with the United States accounts for over 9% of New Zealand exports,23 meaning that New Zealand is still economically beholden to the United States to some extent. That is, even if New Zealand actively opposes American nuclear policy, their economy is still partially dependent on trade with the US, so the US can be even more assured that New Zealand will not take any openly hostile or offensive actions towards America. Moreover, exclusion from the umbrella does not automatically qualify New Zealand as America’s enemy. As noted, US-New Zealand bilateral talks have increased and New Zealand has partially rejoined ANZUS in recent years,24 which is another good omen for relations between the two countries.

Sixth, there is reason to doubt the threat credibility of American extended deterrence. In order for the umbrella to be credible, one must ask if the United States would actually sacrifice New York for Auckland. This sacrifice is unlikely. Similarly, it is also unlikely that the United States would sacrifice New York for Sydney, suggesting that Australia’s position under America’s nuclear umbrella may be little more than rhetoric. This questions the entire American nuclear deterrence umbrella, and thus questions American nuclear threat credibility regarding American willingness to use the arsenal it most certainly possesses. I am not qualified to answer such a question, and hopefully the world is never in a situation where this answer is revealed.

I assume the threat of American extended deterrence has some credibility, and that the US would exercise some limited response if Australia were attacked. This means that New Zealand may be missing out on some concrete protection. However, one third of New Zealand’s population lives in their capital city of Auckland, so if Auckland is attacked, it may remove New Zealand from the map, regardless of how many allies they have to retaliate on their behalf.


Parallels with India

New Zealand’s decision to leave ANZUS parallels India’s reluctance to sign the Nuclear Nonproliferation Treaty (NPT).25 Both countries are former English colonies who sacrificed the American umbrella to have greater foreign policy autonomy, but for different reasons. New Zealand does not want nuclear weapons anywhere near its land, and does not feel threatened enough to need nuclear protection. They do not agree with America bringing nuclear-armed ships into their waters, and they stand up for this belief, despite their small size.

Conversely, India desires indigenous nuclear protection and does not want to sign away its right to ever pursue nuclear weapons.26 Furthermore, India does not believe that the NPT will force other states to denuclearize sufficiently, particularly China, and India believes that preventing their nation from having nuclear weapons is racist and neocolonialist.27 Although both states pursued different options, they both made those decisions because they were tired of being pushed around by the hegemonic U.S., and because they valued nuclear policy autonomy more than bowing to the United States’ wishes for their own “protection.”


Divergence from Neighboring Australia

A comparison between Australia and New Zealand’s respective social politics provides a potential explanation for why the two countries chose different nuclear paths. Historically, Australia has tended to be a more socially conservative nation than New Zealand has. New Zealand has a history of prioritizing a socially progressive agenda with regards to LGBT rights, women’s rights, and racial equality. For instance, New Zealand legalized gay marriage in 2013, whereas Australia waited until 2017.28 Also, New Zealand gave women the right to vote 14 years before Australia did (1893 and 1907, respectively). Moreover, New Zealand has an international reputation for prioritizing returning land and agency to it’s native Maori population, whereas Australia did not give Aboriginal citizens the right to vote until 1962.29

Although none of these are specifically related to nuclear policy, they explain New Zealand’s anti-nuclear tendencies because nuclear disarmament is traditionally associated with the political left.30 Even in America, the Democratic Party and Green Party actively pursue agendas of nonproliferation and/or disarmament,31 whereas the Republican Party advocates for increased nuclear weapons ability as a significant part of American national security.32 As proven by the aforementioned examples, the political left has more of a stronghold on social issues in New Zealand than it does in Australia. This leftward lean is also illustrated by the prominence of the Anti-Nuclear movement in New Zealand, especially when contrasted with Australia’s implicitly right-leaning contemplation of pursuing nuclear weapons in 1956.33 Although the nuclear-free movement also existed in Australia, it gained much more ground in New Zealand – so much so, in fact, that Prime Minister David Lange declared New Zealand a nuclear-free zone in 1978, as was mentioned before.

Given this movement in particular, as well as the overall respective political tendencies of both nations, it follows that New Zealand citizens have a stronger opposition to nuclear weapons than Australian citizens. This opposition lead the anti-nuclear movement to become a much more significant political priority in New Zealand than it ever became in Australia, which explains the two nations’ divergent decisions about their respective ANZUS memberships. As noted, Australia in fact considered pursuing nuclear weapons in 1956, but was dissuaded by the ANZUS treaty’s offer of American nuclear protection. Conversely, while New Zealand initially signed the treaty for that same American protection, they left because the treaty required them to allow nuclear-armed US warships into New Zealand waters, which went against the morals of the anti-nuclear movement.  Although Australia and New Zealand have many similarities in terms of location, wealth, colonization, and ethnic and cultural makeup, their difference in social politics and New Zealand’s stronger anti-nuclear movement make it easy to see how the two countries chose different positions regarding the American nuclear deterrence umbrella.

In conclusion, New Zealand was never an imperial power or colonizer, it does not have significant adversaries, and it is a primarily white, relatively wealthy, first world nation. Furthermore, it is a small nation in a relatively stable geopolitical region, located far away from most other countries. As such, New Zealand is not under any significant nuclear threat, barring North Korean surprises, so their exclusion from the American “umbrella” is not an issue. Ultimately, this exclusion gives New Zealand a more autonomous foreign policy without sacrificing a significant amount of national security at the moment.




  1. Amy L. Catalinac, “Why New Zealand Took Itself out of ANZUS: Observing “Opposition for

Autonomy” in Asymmetric Alliances” (Foreign Policy Analysis, Volume 6, Issue 4 (1 Oct. 2010)). 319.

  1. International Law and Policy Institute. “Nuclear Umbrella States” (International Law and

    Policy Institute, Vol. 4 (Dec. 2011)). 1.

  1. David Alexander, “U.S. Lifts Ban on New Zealand Warships, New Zealand Keeps Nuclear-

free Stance,” Chicago Tribune, 21 Sep. 2012, http://articles.chicagotribune.com/2012-09-21/news/sns-rt-us-defense-panettabre88k031-20120920_1_nuclear-warships-nuclear-free-washington-and-wellington

  1. Ibid.
  2. Catalinac, 319.
  3. Scott Sagan, “Why Do States Build Nuclear Weapons?” (International Security, Vol. 21, No.

3 (Winter, 1996 – 1997)). 55. http://www.jstor.org/stable/2539273

  1. Kenneth Waltz, The Spread of Nuclear Weapons: An Enduring Debate (New York: W. W.

Norton and Company, Inc., 2013). 34.

  1. Richard C. Bush, “U.S. Nuclear and Extended Deterrence: Considerations and Challenges,”

Brookings Institute, Arms Control and Non-Proliferation Series, 7 June 2010, https://www.brookings.edu/research/u-s-nuclear-and-extended-deterrence-considerations-and-challenges/

  1. Ibid
  2. Catalinac, 334.
  3. ibid
  4. Sagan, 55.
  5. Stats New Zealand, “History,” Stats New Zealand, 2 Sep. 2017,


  1. Sagan, 55.
  2. Stats New Zealand, “Economy,” Stats New Zealand, 18 Sep. 2017,


  1. Winston Peters, “Peters: Seismic Change for NZ’s Foreign Service,” Scoop Parliament, 16

Apr. 2008, http://www.scoop.co.nz/stories/PA0804/S00406.htm

  1. Ibid
  2. Sagan, 55.
  3. David McCraw, “New Zealand Foreign Policy Under the Clark Government: High Tide of

Liberal Internationalism” (Pacific Affairs, Vol. 78, No. 2, Summer 2005). 219.

  1. Aaron David Miller and Richard Sokolsky, “The ‘Axis of Evil’ is Back,” CNN, 26 Apr.

2017, https://www.cnn.com/2017/04/26/opinions/axis-of-evil-is-back-miller-sokolsky/index.html

  1. Bush.
  2. Ankit Panda, “What’s In New Zealand’s New 2016 Defense White Paper?” The Diplomat,

13 June 2016, https://thediplomat.com/2016/06/whats-in-new-zealands-new-2016-defense-white-paper/

  1. Stats New Zealand, “Economy.”
  2. Alexander.
  3. George Perkovich, India’s Nuclear Bomb: the Impact on Global Proliferation (Berkeley:

University of California Press, 1999), 126.

  1. Ibid
  2. Ibid
  3. Damien Cave and Jacqueline Williams, “Australia Makes Same Sex Marriage Legal,” New

York Times, 7 Dec. 2017, https://www.nytimes.com/2017/12/07/world/australia/gay-marriage-same-sex.html

  1. Australian Electoral Commission, “Electoral Milestones for Indigenous Australians,”

Australian Electoral Commission, 10 Oct. 2017, https://www.aec.gov.au/indigenous/milestones.htm

  1. Thomas Rochon, Mobilizing for Peace: The Anti-Nuclear Movements in Western Europe (Princeton: Princeton University Press, 2014), 156.

31. Greg Mercer, “The 2016 Democratic and Republican Platforms Have Things to Say About

Nuclear Weapons,” The Pandora Report, 22 Jul. 2016, https://pandorareport.org/2016/07/22/the-2016-democratic-and-republican-platforms-have-things-to-say-about-nuclear-weapons/

  1. Ibid
  2. International Law and Policy Institute.


Works Cited

Alexander, David. “U.S. Lifts Ban on New Zealand Warships, New Zealand Maintains Nuclear-

free Stance.” Chicago Tribune, 21 Sept. 2012. http://articles.chicagotribune.com/2012-09-21/news/sns-rt-us-defense-panettabre88k031-20120920_1_nuclear-warships-nuclear-free-washington-and-wellington

Bush, Richard C. “U.S. Nuclear and Extended Deterrence: Considerations and Challenges.”

Brookings Institute, Arms Control and Non-Proliferation Series (7 June 2010). https://www.brookings.edu/research/u-s-nuclear-and-extended-deterrence-considerations-and-challenges/

Catalinac, Amy L. “Why New Zealand Took Itself out of ANZUS: Observing “Opposition for

Autonomy” in Asymmetric Alliances,” Foreign Policy Analysis, Volume 6, Issue 4 (1 Oct. 2010), p. 317–338. https://doi.org/10.1111/j.1743-8594.2010.00115.x

Cave, Damien and Jaqueline Williams. “Australia Makes Same Sex Marriage Legal.” New York

Times, 7 Dec. 2017. https://www.nytimes.com/2017/12/07/world/australia/gay-marriage-same-sex.html

International Law and Policy Institute. “Nuclear Umbrella States.” International Law and Policy

Institute, Vol. 4 (Dec. 2011), p. 1-2. http://nwp.ilpi.org/wp-content/uploads/2015/03/NP04-11-UmbrellaStates.pdf

McCraw, David. “New Zealand Foreign Policy Under the Clark Government: High Tide of

Liberal Internationalism.” Pacific Affairs, Vol. 78, No. 2 (Summer 2005), p. 217-235.

Mercer, Greg. “The 2016 Democratic and Republican Platforms Have Things to Say About

Nuclear Weapons.” The Pandora Report, 22 Jul. 2016. https://pandorareport.org/2016/07/22/the-2016-democratic-and-republican-platforms-have-things-to-say-about-nuclear-weapons/

Miller, Aaron David & Rickard Sokolsky. “The ‘Axis of Evil’ is Back.” CNN, 26 Apr. 2017.


Panda, Ankit. “What’s In New Zealand’s New 2016 Defense White Paper?” The Diplomat, 13

June 2016. https://thediplomat.com/2016/06/whats-in-new-zealands-new-2016-defense-white-paper/

Perkovich, George. India’s Nuclear Bomb: the Impact on Global Proliferation. Berkeley:

University of California Press, 1999.

Peters, Winston. “Peters: Seismic Change for NZ’s Foreign Service.” Scoop Parliament, 16 Apr.

  1. http://www.scoop.co.nz/stories/PA0804/S00406.htm

Sagan, Scott D. “Why Do States Build Nuclear Weapons?” International Security, Vol. 21, No. 3

(Winter, 1996 – 1997), pp. 54 – 86. http://www.jstor.org/stable/2539273

Sagan, Scott D. and Kenneth N. Waltz. The Spread of Nuclear Weapons: An Enduring Debate.

3rd ed. New York: W. W. Norton & Company, Inc., 2013.

Stats New Zealand, “Econocy.” Stats New Zealand, 18 Sep. 2017.


Stats New Zealand, “History.” Stats New Zealand, 2 Sep. 2017.


Rochon, Thomas. Mobilizing for Peace: The Anti-Nuclear Movements in Western Europe.

Princeton: Princeton University Press, 2014.


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