By Melissa Parke
Nuclear weapons and the decades-long effort to restrain and ultimately eliminate them have reached an alarming inflection point.
The risk that these weapons could be used in conflict has increased to its highest level since the Cold War, largely due to Russia’s nuclear threats during the early days of its full-scale invasion of Ukraine and to an expansion of the dangerous practice of nuclear sharing. Meanwhile, bilateral arms control agreements put in place to ensure stability have been atrophying.
Looking back, it is clear that nuclear arms control reached an apogee in the 1990s with the first and second strategic arms reduction treaties between the United States and the Soviet Union/Russia and with multilateral agreements such as the Open Skies Treaty, the Chemical Weapons Convention, and the Comprehensive Test Ban Treaty (CTBT).
The rot started to set in at the turn of the century when the United States abrogated the Anti-Ballistic Missile Treaty in 2002. More recently, the dismantling of further bilateral agreements between the United States and Russia accelerated with the Trump administration’s withdrawal from the Intermediate-Range Nuclear Forces Treaty in 2019 and Russia’s withdrawal from the Treaty on Conventional Armed Forces in Europe last year.
Also in 2023, Russia “suspended” its participation in the New Strategic Arms Reduction Treaty (New START) by refusing to allow U.S. inspections of its nuclear facilities. The agreement remains on the books, and Russia says it will abide by the prescribed warhead limits, but the treaty is due to expire in two years with no prospect of a successor agreement given the current hostility between the two countries.
Although the cornerstone of multilateral nuclear disarmament architecture, the nuclear Nonproliferation Treaty (NPT), remains in force, it has stalled with no agreement since 2010 on ways to move the treaty forward. One example of the dysfunction was the 2015 NPT Review Conference, which could not agree on a final outcome document. The main reasons were differences over demands for a conference on creating a nuclear-weapon-free zone in the Middle East and the refusal of the five NPT nuclear-weapon states (China, France, Russia, the United Kingdom, and the United States) to agree on a timetable for implementing their commitment to disarm under Article 6 of the treaty.1
The 2022 review conference, which was delayed from 2020 by the COVID-19 pandemic, failed because Russia refused to agree to references in the final document about Ukraine, which it had invaded a few months earlier. Even if the meeting were held before Moscow launched its full-scale war, many experts believe the prospects for agreement were slim because the non-nuclear-weapon states were frustrated at the lack of movement on disarmament by the nuclear-weapon states.2
Although signed by nearly all states, the CTBT has never entered into force because several key countries that are required to ratify it, including nuclear-armed China, India, Israel, North Korea, Pakistan, and the United States, have not done so. The treaty was dealt a further blow last year when Russia revoked its ratification, part of its strategy to ratchet up pressure on NATO and the United States over Ukraine.
A New Push for Disarmament
Despite the gloomy picture painted by these developments, there is reason for optimism that multilateral arms control has a brighter future. That is because a new, progressive, multilateral push for nuclear disarmament has been gathering momentum with the negotiation, adoption, and entry into force of the Treaty on the Prohibition of Nuclear Weapons (TPNW), which took place between 2017 and 2021.
The TPNW complements the NPT and provides an internationally agreed framework to realize the aim of that treaty, which is not just to prevent the spread of nuclear weapons but ultimately to achieve nuclear disarmament. It does that by filling a gap in the NPT that has allowed the five nuclear-armed states to retain their weapons while banning other states from acquiring them. In exchange, the nuclear-armed states promised to disarm and to support the non-nuclear-weapon states with nuclear energy for peaceful purposes. The TPNW builds on this NPT bargain by banning countries from developing, testing, producing, manufacturing, transferring, possessing, stockpiling, using, and threatening to use nuclear weapons or allowing nuclear weapons to be stationed on their territory. It also prohibits them from assisting, encouraging, and inducing anyone to engage in these activities.3
A country that possesses nuclear weapons may join the treaty, but must agree to destroy its arsenal in accordance with a legally binding, time-bound plan that includes all necessary verification mechanisms. Similarly, a country that hosts another country’s nuclear weapons on its territory may join the treaty if it agrees to remove the weapons by a specified time.
The roots of the TPNW are in the international initiative on the humanitarian impact of nuclear weapons started at a conference in Oslo in 2013 attended by 128 states, UN agencies, other international organizations, and civil society.4 This was followed by meetings in Nayarit, Mexico, and Vienna the following year. Out of these meetings came the idea of a new international treaty to outlaw nuclear weapons because they are the most destructive, inhumane, and indiscriminate weapons ever created, both in the scale of the devastation they cause and in their uniquely persistent, spreading, genetically damaging radioactive fallout. They are unlike any other weapons, including chemical and biological weapons, which were already subject to bans under multilateral treaties.
At the heart of the TPNW lies a focus on the lasting harm caused by nuclear weapons that was inspired by treaties banning landmines and cluster munitions. It took time to gather the signatures and ratifications for these earlier accords, adopted in 1997 and 2008, respectively, and it was always anticipated that the TPNW would take time to garner support in the same way.
Several major states whose armed forces used landmines and cluster munitions joined those treaties because their alleged military value and reputational cost is outweighed by the benefits of giving them up, namely increased diplomatic influence and soft power. Among their number are nuclear-armed France and the UK, as well as other NATO countries that endorse the use of nuclear weapons in their national defense policies. The implication is that these countries accept the principle that a category of weapons that cause lasting harm and are morally repugnant can and should be prohibited. The expectation is that as more countries join the TPNW, the pressure will grow on the nuclear-armed states to follow suit. Already, some NATO countries, including Germany, which hosts U.S. nuclear weapons on its territory, have attended the meetings of TPNW states-parties as observers.5
The TPNW also is rooted in the taboo against the use of nuclear weapons that developed after knowledge spread, despite U.S. attempts at censorship, of what happened to the people of Hiroshima and Nagasaki when their cities were attacked with the first nuclear bombs. A strong international consensus accepts that this taboo has helped restrain leaders from using nuclear weapons again. The TPNW effectively codifies the nuclear taboo and takes it a step further by banning the weapons outright.6
So far, of 197 eligible states, 93 states have signed the TPNW, and 69 states have ratified or acceded to it. At the recent meeting in New York, Indonesia reported that its parliament has voted to ratify the treaty; several other delegations, including that of Brazil, said that their governments will be doing so very soon. This is the same number that had signed and ratified the NPT at this stage in the universalization process. Although the nine states that now possess nuclear weapons (the five recognized under the NPT along with India, Israel, North Korea, and Pakistan) remain opposed to joining the TPNW, proponents expect that, through a process of stigmatization and delegitimization, the treaty can convince the nine and their allies that it is in all of their interests to join the treaty and eliminate nuclear weapons.7
The TPNW Gains Strength
Since coming into force in 2021, the TPNW has continued to grow in strength. It just completed a successful second meeting of its member states in New York and is about to pass the milestone of having more than half of the world’s countries on board either as TPNW signatories or fully ratified members.
The treaty’s success derives partly from its rejection of the misguided theory of nuclear deterrence. Also important is the TPNW’s fresh approach, marked by inclusiveness and transparency, to verification and to advancing an agenda for nuclear justice based on recognizing the harm that nuclear weapons have done to human health and the environment. In addition to the 215,000 people estimated to have been killed at Hiroshima and Nagasaki, between 1945 and 2017, Russia, the United States, and other nuclear-weapon states conducted more than 2,000 nuclear weapons tests that contaminated extensive areas around the world that extend well beyond the test sites, making them uninhabitable and causing widespread intergenerational harm to people’s health.8
The TPNW directly challenges deterrence with its prohibition on the use and threat of use of nuclear weapons. This principle enabled treaty member states to issue a strong condemnation of nuclear threats at their first meeting in 2022, following Russia’s nuclear saber-rattling regarding Ukraine. The TPNW language has been echoed since by the Group of 20 countries and by individual leaders, including Chinese President Xi Jinping, German Chancellor Olaf Scholz, and NATO Secretary-General Jens Stoltenberg.9 Nuclear experts assess that these condemnations persuaded Russia to stop making overt nuclear threats and thus demonstrated that the stigmatization of nuclear weapons-related actions does influence the behavior of nuclear-armed states.10
The political declaration from the 2023 states-parties meeting reiterated this condemnation of nuclear threats, criticized nuclear sharing among states, and, most notably, strongly denounced the doctrine of nuclear deterrence as a threat to human security and an obstacle to nuclear disarmament.11 This marked the first time that the members of a multilateral treaty have taken such a position on deterrence. Although fundamental to the nuclear doctrines of the nuclear-weapon states, deterrence is an unproven theory that endangers the future of humanity, based as it is on the implicit threat to use nuclear weapons. Thus, the TPNW is breaking new ground given that previous arms control and disarmament treaties did not in any way challenge the doctrine of deterrence.
The states-parties also commissioned a report from the TPNW’s scientific advisory group, working with member states, the International Campaign to Abolish Nuclear Weapons (ICAN), and the International Committee of the Red Cross, on the threat from nuclear weapons and the doctrine of deterrence. It is to be submitted to the next meeting of TPNW states-parties in 2025. In the words of the decision document,12 this report is “[t]o challenge the security paradigm based on nuclear deterrence by highlighting and promoting new scientific evidence about the humanitarian consequences and risks of nuclear weapons and juxtaposing this with the risks and assumptions that are inherent in nuclear deterrence.”
The TPNW is the only treaty that provides a pathway to verified disarmament, through Article 4. The working group on this article,13 co-chaired by Mexico and New Zealand and supported by the scientific advisory group and civil society, is developing a verification mechanism for when a nuclear-armed state or a state that hosts nuclear weapons joins the treaty.
There are lessons on verification to be learned from past and existing bilateral arm control treaties, but the TPNW is innovating and taking a whole-of-society approach derived from the treaty’s commitment to irreversible, verifiable, and transparent disarmament. That differs from bilateral arms control verification measures in treaties that aim to limit the size and categories of nuclear stockpiles, rather than eliminate them altogether. These other treaties were based on assumptions of distrust and secrecy designed to preserve the integrity of nuclear weapons systems and deterrence.14
The TPNW’s break with the traditional secrecy surrounding nuclear weapons is a welcome one. It should set an example for other nuclear arms agreements, which need to acknowledge that democratic practice is not something that ends when a government is elected or appointed. Rather, when it comes to matters of life and death affecting the whole of society, transparency is essential politically and morally.
Another innovative TPNW approach to disarmament is its plan to advance nuclear justice by mandating member states, under Articles 6 and 7, to provide assistance to communities harmed by the use, testing, and development of nuclear weapons and to clean up the radioactive contamination that remains in many regions. Given that nuclear testing has disproportionately affected Indigenous and colonized peoples, the treaty seeks to right the wrongs of the past.
Survivors and affected communities are actively engaged in the work of the treaty and participate in its proceedings. This underscores the treaty’s commitment to set itself apart from other nuclear agreements that are dominated by governments and military bureaucracies. The TPNW recognizes that given that nuclear weapons threaten all of society, all of society should have a role in decisions about how to manage, control, and eliminate the arsenals.
The recent meeting of TPNW member states heard testimony from affected communities, which delivered an unprecedented joint statement.15 The meeting produced a decision that Kazakhstan and Kiribati, two states affected by Soviet, UK, and U.S. nuclear testing, will continue to lead the working group on Articles 6 and 7. It also produced an agreement that discussion on establishing an international trust fund for victim assistance and environmental remediation will continue, with a recommendation to be made at the next TPNW meeting in March 2025.
The Hope of Multilateral Arms Negotiations
Washington and Moscow still control 90 percent of the global nuclear stockpile and traditionally have sought to make arms control decisions between themselves, but the prospects of Russian-U.S. cooperation on a treaty to succeed New START are dim. At the same time, although the United States made a proposal in June 2023 for arms control talks with China, this too seems a nonstarter, given that both countries seem intent on modernizing their arsenals and China on increasing its stockpile. To avoid a new nuclear arms race and eliminate the threat posed by the existence of nuclear weapons, the way forward will depend on multilateral arms negotiations that go further than limiting stockpiles and delivery systems.
As the TPNW continues to gain more members, the nuclear-armed states and their allies that endorse the use of nuclear weapons in their security doctrines will face increasing political and diplomatic pressure to engage with the treaty. Much of their opposition to the TPNW, before its negotiation and afterward, has been based explicitly and correctly on concerns that the treaty would have the effect of delegitimizing nuclear weapons and nuclear deterrence.
This is why when pursuing their national aims, even nuclear-armed states make serious efforts to justify their actions under international law and portray them as normal, accepted practice that follows established precedents. For example, all NPT nuclear-weapon states claim to be complying fully with NPT disarmament obligations and international humanitarian law.
In the past few decades, nearly all nuclear-armed states have joined the biological and chemical weapons conventions, which demonstrates that they see weapons of mass destruction as unnecessary and morally unacceptable. Therefore, they already have accepted the argument that weapons that cause indiscriminate, lasting harm can and should be eliminated.
In the best of circumstances, it will take time before the nuclear-weapon states fully embrace the TPNW. Although this outlook could be discouraging, it is worth remembering that China and France ultimately joined the NPT, even if it took more than 20 years. There are compelling reasons to be optimistic about the TPNW’s future. Increasingly, it is apparent that, in this treaty, the nuclear-armed states have a viable route, established in international law, through which to achieve disarmament fairly and verifiably and to finally eliminate what they all know is the existential threat that nuclear weapons pose to the whole world.
4. See Government of Norway, “Conference: Humanitarian Impact of Nuclear Weapons,” March 11, 2013, https://www.regjeringen.no/en/historical-archive/Stoltenbergs-2nd-Government/Ministry-of-Foreign-Affairs/humimpact_2013/id708603/.
6. Nina Tannenwald, “The Great Unraveling: The Future of the Nuclear Normative Order,” in Meeting the Challenges of the New Nuclear Age (Cambridge, MA: American Academy of Arts and Sciences, 2018), pp. 6-31, https://www.amacad.org/sites/default/files/publication/downloads/New-Nuclear-Age_Emerging-Risks.pdf.
7. International Campaign to Abolish Nuclear Weapons (ICAN), “How the Treaty Works,” n.d., https://www.icanw.org/how_the_tpnw_works (accessed December 15, 2023).
9. Indian Ministry of External Affairs, “G20 New Delhi Leaders’ Declaration,” n.d., https://www.mea.gov.in/Images/CPV/G20-New-Delhi-Leaders-Declaration.pdf (meeting held September 9-10, 2023); Stuart Lau, “China’s Xi Warns Putin Not to Use Nuclear Arms in Ukraine,” Politico, November 4, 2022, https://www.politico.eu/article/china-xi-jinping-warns-vladimir-putin-not-to-use-nuclear-arms-in-ukraine-olaf-scholz-germany-peace-talks/; Madeline Chambers, “Germany’s Scholz: Trying to Prevent Escalation in Russia-Ukraine War,” Reuters, September 21, 2022; “Opening Remarks by NATO Secretary General Jens Stoltenberg at a Meeting of the Group of the Progressive Alliance of Socialists & Democrats in the European Parliament,” NATO, September 28, 2022, https://www.nato.int/cps/en/natohq/opinions_207645.htm.
10. Pavel Podvig, “Why a Russian Nuclear Expert Thinks the Doomsday Clock Should Move Away From Midnight,” Bulletin of the Atomic Scientists, November 8, 2023, https://thebulletin.org/2023/11/why-a-russian-nuclear-expert-thinks-the-doomsday-clock-should-move-away-from-midnight/.
11. Second Meeting of States Parties to the Treaty on the Prohibition of Nuclear Weapons, “Revised Draft Declaration of the Second Meeting of States Parties to the Treaty on the Prohibition of Nuclear Weapons: ‘Our Commitment to Upholding the Prohibition of Nuclear Weapons and Averting Their Catastrophic Consequences,’” TPNW/MSP/2023/CRP.4/Rev.1, December 1, 2023.
12. Second Meeting of States Parties to the Treaty on the Prohibition of Nuclear Weapons, “Decisions to Be Taken by the Second Meeting of States Parties to the Treaty on the Prohibition of Nuclear Weapons,” TPNW/MSP/2023/CRP.3/Rev.1, November 30, 2023.
13. ICAN, “TPNW Informal Working Group: Article 4 - Nuclear Disarmament Verification,” n.d., https://www.icanw.org/tpnw_intersessional_work_article_4_nuclear_disarmament_verification (accessed December 15, 2023).
14. Pavel Podvig, ed., “Verifying Disarmament in the Treaty on the Prohibition of Nuclear Weapons,” UN Institute for Disarmament Research, 2022, https://unidir.org/wp-content/uploads/2023/05/UNIDIR_Verifying_Disarmament_TPNW.pdf.
15. “Affected Communities Statement to the Second Meeting of States Parties to the UN Treaty on the Prohibition of Nuclear Weapons, 2023,” n.d., https://icanw.org.au/wp-content/uploads/Affected-Communities-Statement-poster-final.pdf (poster).