The Third Meeting of States Parties (3MSP) to the Treaty on the Prohibition of Nuclear Weapons (TPNW) took place at the United Nations headquarters in New York City March 3-7. A large and diverse group of stakeholders convened, including 86 countries and over a thousand representatives from 163 civil society organizations. The week included rich discussions in plenary sessions and numerous side events hosted by state delegations and civil society groups.
The treaty, which entered into force in 2021, is the first to place a full ban on the possession, use, or testing of nuclear weapons. With 73 states parties and 94 signatories, the treaty is now just one country shy of a global majority. A unique aspect of the treaty that sets it apart from other nuclear weapons agreements is its emphasis on humanitarian and environmental impacts of nuclear weapons and centering of affected community voices. The 3MSP, for example, was presided over by Kazakhstan, whose environment and citizens have been affected by Russian nuclear explosive tests.
The 3MSP took place at a time of increased geopolitical and historical significance. The final political declaration adopted at the conclusion of the week noted the increasing risk of nuclear war, with growing nuclear arsenals, modernization programs, and nuclear saber rattling around the world. This year also marks the 80th anniversary of the first testing and use of nuclear weapons – and relatedly, FAS’s founding.
Welcomed Advancements of the Past Year
Over the past year, the campaign to abolish nuclear weapons has experienced numerous wins that were celebrated at the Meeting of State Parties. New ratifications of the treaty by Indonesia, São Tomé and Príncipe, Sierra Leone, and Solomon Islands brought the number of states parties to just one shy of a global majority. During the intersessional period, working groups established in the Vienna Action Plan and further strengthened at 2MSP continued work on universalization, establishing an international trust fund for research and medical compensation for affected communities, and creating verification measures for states to disarm.
Possibly the most well-earned achievement of the year came from Nihon Hidankyo, a Japanese organization of survivors of the atomic bombings of Hiroshima and Nagasaki (known as “Hibakusha”), which won the 2024 Nobel Peace Prize for advocating against nuclear weapons use through personal testimony. Nihon Hidankyo has long supported the TPNW, and several members were in attendance at the 3MSP to share their stories at side events, stand in solidarity with other affected communities, and support the treaty’s implementation.
Other United Nations actions this year worked towards a world free from nuclear weapons. The UN General Assembly Resolution for a new scientific study on the consequences of nuclear war passed with 136 votes in favor, 3 against and 29 abstentions. The resolution’s call for researching climatic, environmental, and health consequences aligns with the TPNW’s focus on humanitarian consequences of nuclear war. The overwhelming majority of global states voting in favor of the resolution also indicated a motivation by non-nuclear states for a world without nuclear weapons. The UN Summit of the Future also reaffirmed the call for disarmament in its Pact for the Future.
Concerning Developments
In recent years, geopolitical tensions and disruptive technologies have heightened the risk of nuclear war. In January, the Bulletin of the Atomic Scientists moved the Doomsday Clock closer to midnight; at 89 seconds, the clock is the closest it has ever been to the metaphorical apocalypse. Every single nuclear-armed state is advancing their nuclear forces in number or in capabilities.
The Trump administration has proposed new costly military programs like the Iron Dome missile defense system. The program could spur additional Chinese and Russia nuclear buildup as they ensure deterrence capabilities that are designed to outsmart the missile defense system. In addition, the administration’s seeming abandonment of allies have led to a call by some European and Asian state leaders to increase defense spending and consider the development of their own nuclear weapons.
In general, the global appetite for arms control and nonproliferation has decreased. There have been no clear moves to revitalize the New START treaty since Russia suspended its participation in 2023. U.S. efforts to engage in risk reduction talks with China have also not been successful as China is not convinced nuclear arms control is in their security interests. There does not appear to be any efforts between the United States and Russia to negotiate a follow-on treaty to New START, which expires in February 2026 and is the last remaining treaty constraining the deployed arsenals of the two largest nuclear powers. The past two Nonproliferation Treaty Review Conferences have failed to reach final consensus documents. Combined with the reduction in diplomatic efforts between nuclear states, emerging technologies like artificial intelligence create instability and an increased risk of miscalculation or misunderstanding that could lead to nuclear use.
States demonstrated their increased reliance on nuclear weapons in their military strategy through spending, rhetoric, and exercises in 2024. For example, ICAN’s Global Nuclear Weapons Spending report published in 2024 found that in 2023 the nine nuclear weapons states spent 91.4 billion on nuclear weapons, an increase of 13.4 % from the previous year, and projected that 2024 spending would surpass $100 billion.
3MSP Discussions and Decisions
The international trust fund for affected communities was a topic of much discussion at the Meeting. Communities in the Pacific island nations, Kazakhstan and the continental United States face many illnesses and health complications from radioactive fallout from explosive nuclear testing. From 1949 to 1989, the Soviet Union conducted about 456 nuclear tests near the Kazakh city of Semy, resulting in birth defects, a multitude of cancers, and immune disorders in generations of nearby residents. The United States, United Kingdom, and France conducted 318 tests across the Pacific, causing environmental damage, forcibly displacing communities, and health consequences. The United States conducted an additional 928 tests on the continental United states, irradiating residents across the West. The purpose of the international trust fund will be to fund community health studies related to nuclear weapons impacts that will inform humanitarian assistance subsequently provided by the fund. The working group in charge of planning and preparing the fund will also provide a report no later than four months before the first review conference of the TPNW on the technical provisions for the fund.
The 3MSP decided that the first review conference for the Treaty will be held in New York City November 30–December 4, 2026 with South Africa presiding. Before then, states expect productive work again in the intersessional period. This will include work on the universalization of the treaty, led by Austria, New Zealand, and Uruguay; victim assistance and environmental remediation again led by Kazakhstan and Kiribati; and the creation of an international authority for verification led by Malaysia and the Philippines.
Representatives and allies of communities affected by uranium mining and milling expressed concerns that the TPNW preamble text which protects “the research, production, and use of nuclear energy for peaceful purposes” is in contention with providing full nuclear justice and prevents trust fund compensation to all affected communities.
A working paper submitted by 44 civil society organizations expressed that nuclear technologies from “cradle to grave” impact public health and the environment. Noting that uranium mining and milling overwhelmingly occurs on indigenous lands, the groups advocated for the acknowledgement that all nuclear technologies, due to the requisite uranium resources, have the potential to cause contamination to environments and negative health consequences.
Both Marshall Islands official state and civil society representatives also called for structural changes within the treaty. The Marshall Islands, where the United States conducted over 33 nuclear explosive tests, are severely contaminated by radioactive fallout, resulting in high rates of health issues like cancers, birth defects, and immune disorders among the population and forced displacement of residents as the fallout relegated certain areas uninhabitable. The Marshall Islands support the efforts of the TPNW, but have not ratified the treaty.
The delegation from the Marshall Islands argued that the language in Article 6 of the treaty does not adequately place burden on the United States for environmental remediation for nuclear testing. In his statement, the Marshallese Ambassador said the TPNW “wrongfully absolves responsibility for the consequences of nuclear weapons testing from those states which conducted the nuclear testing. And instead leaves us responsible to pay for billions of dollars of adjudicated impacts which we did not choose.” While states that support the treaty do stand in solidarity with each other, they do not have monolithic views about the correct implementation or structure.
Many of the working papers written by affected communities also call for the international trust fund to be open to non-state parties, which would increase engagement with the treaty and open opportunities for further compensation to impacted communities.
Numerous side events featured a coalition of affected communities in an impressive show of solidarity. For example, the Bikini Day Side Event: “Damage of Nuclear Weapons and Urgent Need for Relief – Nuclear Sufferers Speak,” featured Japanese and Korean Survivors of the Hiroshima and Nagasaki bombings, Pacific island communities affected by nuclear testing, Marshall Islanders, and Gilbertese representatives. While originally the term “hibakusha” translated in Japanese to bomb-affected people and referred specifically to survivors from Hiroshima and Nagasaki, this term has been widely shared with and adopted by other impacted communities. Regardless of whether it was Japanese bomb survivors or downwinders from tests before and after, both communities share the pain of a bomb dropping on their land. The solidarity and respect to all affected populations and generations demonstrates the dedication to a united front for a world without nuclear weapons.
As 2025 is the 80th year since the U.S. bombing of Hiroshima and Nagasaki, many of the original atomic bomb survivors have since passed. While many within the Hibakusha community worried that future generations would be too preoccupied with other issues like the economy and climate change to continue advocating for a world without nuclear weapons, there remains a strong and vibrant youth movement against the bomb that carries forward on the testimony of survivors. During the Youth for TPNW side event, youth delegates heard from a Hibakusha who was just 2 years old when the United States dropped an atomic bomb on her hometown of Nagasaki. She said, “today’s listeners are tomorrow’s storytellers.”
Over the past year, the campaign to abolish nuclear weapons has experienced numerous wins that were celebrated at the Meeting of State Parties.
China is NOT a nuclear “peer” of the United States, as some contend.
China’s total number of approximately 600 warheads constitutes only a small portion of the United States’ estimated stockpile of 3,700 warheads.
Dr. Lim will help develop, organize, and implement FAS’s growing contribution in the area of catastrophic risk including on core areas of nuclear weapons, AI and national security, space, and other emerging technologies.
Moreover, the recent decrease in UK government transparency regarding the status of its nuclear arsenal and modernization program reflects a worrisome global trend.