An alternative governance framework is needed—one that can regulate the growing AI industry’s international security impact as a global externality.

April 2025
By Yanliang Pan and Daihan Cheng

The popularization of DeepSeek has ushered in a paradigm shift in the field of large language models (LLMs). The prior assumption that only billion-dollar companies with access to troves of computing hardware could train and deploy these powerful frontier artificial intelligence (AI) models simply no longer holds true. Not only is the high-performance Chinese model cheap to train and easy to deploy on local hardware, it is also open source, meaning that anyone can modify its parameters, or fine-tune the model, to perform specific tasks.

DeepSeek and other large language models that are cheap to train and easy to deploy on local hardware could be a big help to a nonstate actor seeking to develop a weapon of mass destruction. (Photo by Nicolas Economou/NurPhoto via Getty Images)

For a nonstate actor seeking to develop a weapon of mass destruction (WMD), such a model would be the perfect assistant. The fact that high-performance frontier AI models no longer have to rely on cloud connection to massive data centers means that the detection of misuse for chemical, biological, radiological, or nuclear (CBRN) proliferation has gone out the window, along with the possibility of enforcing safety guardrails against problematic responses or verifying the model’s end use. Clearly, an approach to AI-CBRN risk governance based on the model of nuclear arms verification or nonproliferation safeguards1 is no longer sufficient. It is time to borrow an alternative frame from humanity’s experience tackling a different existential challenge, namely, that of climate change. That alternative frame is the economics of externalities.

Risks and Governance Challenges

The CBRN risks associated with AI misuse are real and numerous. While investigating its GPT-4 model’s CBRN proliferation potential, U.S.-based OpenAI concluded that “a key risk driver is GPT-4’s ability to generate publicly accessible but difficult-to-find information, shortening the time users spend on research and compiling this information in a way that is understandable to a nonexpert user.”2 Red-teaming exercises also have demonstrated the ability of LLMs to help nonexperts quickly identify dangerous pathogens suitable for a biological weapons attack.3 Similar challenges apply in the chemical and radiological contexts.

Beyond proliferation risks, malicious actors could exploit increasingly capable frontier AI models to augment cyber offensives that compromise the safety and security of critical nuclear infrastructure and supply chains.4 Meanwhile, AI-augmented disinformation and spoofing could increase the risk of inadvertent escalation by distorting states’ perception of their adversaries’ strategic intentions and capabilities. It also could undermine public communication in a CBRN emergency, misleading the response or “worsening the emergency’s consequences” by “[amplifying] public anxiety and [increasing] confusion.”5 The list of CBRN risks associated with AI misuse by malicious actors goes on.

International institutions and multilateral forums specializing in CBRN governance are not ready to confront these emerging risks. Take the nuclear domain as an example. The foundational forums for multilateral deliberations over nuclear disarmament and nonproliferation—including the nuclear Nonproliferation Treaty (NPT) review process, the Conference on Disarmament, and the First Committee of the UN General Assembly—are either trapped in geopolitical gridlock or bound to conservatism by the need for consensus.

Participants chat in front of an electronic image of a soldier at the Responsible AI in the Military Domain (REAIM) summit in Seoul in September. The summit, as with most multilateral discussions on AI, focused on the risks of military AI but the technology can also be used to mitigate the proliferation of weapons of mass destruction, authors Yanliang Pan and Daihan Cheng write. (Photo by Jung Yeon-Je/AFP via Getty Images)

There is also a lack of technical AI expertise among the diplomats attending these forums as AI talent concentrates in the private sector and in national technology labs. Relevant multilateral deliberations, insofar as they have taken place, have focused largely on the risks of military AI, such as AI-automated nuclear-weapon command and control, while failing to address the full range of challenges and opportunities at the AI-nuclear nexus.

Even if diplomats can agree on a broader governance solution, the technology is ultimately developed and deployed by industry and governed by national regulatory authorities. With the former engaged in a race to enhance model performance at lower costs and the latter reluctant to stifle innovation in a national strategic sector, neither has the bandwidth or the incentive to prioritize the mitigation of seemingly remote nuclear risks. Meanwhile, the International Atomic Energy Agency (IAEA), which is traditionally responsible for nuclear safety, security, and safeguards, has neither the capacity to update its safety and security guidance at the pace frontier AI technologies are advancing, nor the mandate to monitor AI models to which nonstate actors may have access, even if such models may serve as proliferation tools.

Balancing AI Externalities With an Economics Frame

An alternative governance framework is needed—one that can regulate the growing AI industry’s international security impact as a global externality. In economics, an externality is a cost or benefit to a third party that is paid for by neither the producer nor the consumer. The classic example of a negative externality is unregulated industrial pollution as it imposes a cost upon the public that is reflected neither in the cost of production nor in the price of the good that the consumer pays. Similarly, unregulated AI advancements could impose public costs in the form of heightened international security risks, requiring government intervention. The trick is to create incentive mechanisms to reward responsible innovation, akin to the incentive schemes that price in the cost of carbon emissions as a global negative externality of polluting industries.

Several such schemes are available. For instance, carbon pricing, implemented through a carbon tax or a cap-and-trade system, assigns a clear monetary price to each unit of carbon emitted, such that heavy emitters pay more to purchase emissions rights whereas those that reduce their carbon footprints receive a credit.6 Carbon offsets, meanwhile, reward carbon reduction activities anywhere—from reforestation to renewable energy investment—by recognizing their positive social impact with a tradable certificate.7 In 2015, economist William Nordhaus introduced club theory to the regulation of carbon emissions, observing that “modest trade penalties on nonparticipants can induce a coalition” more effectively.8

To be sure, these proposals introduce their own implementation challenges, and not all of them are immediately applicable to regulating the AI industry’s CBRN security impacts. Such impacts are still less than fully understood and, in any case, may not be amenable to deterministic quantification. Nevertheless, these challenges do not negate the fundamental rationale for adapting an economics-based regulatory approach to AI-CBRN risks.

Conceptually, these risks are no more and no less than global negative externalities that the industry has imposed upon the public. Although certain AI developers have voluntarily evaluated the international security impact of their frontier models, the practice is neither common nor adequately incentivized. Most importantly, although traditional state-targeted disarmament and nonproliferation approaches such as arms verification and safeguards may prove adequate for CBRN activities already under state government purview, most AI advances are now industry-led rather than state-led, and approaches based on economic incentives are best suited to the private sector.

What would such an approach look like? One option could involve a global tax on AI developers and consumers, designed to address frontier AI’s existential security impact. The amount of such a tax with respect to an AI product would depend on the product’s evaluated potential to contribute to CBRN risks, thus incentivizing the developer to embed safety features or restrict public access to the most dangerous models.

A moderate tax will not hold back industry innovation; indeed, the efficiency gains introduced by DeepSeek’s innovation have cut LLM costs by as much as 96 percent, and further improvements in hardware and algorithm design are expected.9 But such a tax would beneficially shift the responsibility for CBRN risk mitigation to the AI developer as the party most familiar with the model and most capable of implementing access controls. This would reduce the knowledge and expertise asymmetry between regulators and industry. It also would reward responsible approaches to innovation on the part of AI developers who attempt proactively to minimize the technology’s negative global security impact.

The tax revenue may go toward covering the additional national and international proliferation monitoring and counterproliferation expenditures necessary to maintain prior levels of public safety and security. Governments also could identify and reward an exclusive club of responsible AI innovators with tax credits and free-trade benefits in semiconductor hardware, imposing moderate export controls on entities, and tariffs on countries that fail to perform their due diligence to mitigate AI-CBRN risks.

At the same time, the incentive scheme should also include ample opportunities for offsets. Offset arrangements could reward AI developers for making either monetary or in-kind contributions to counterproliferation efforts. These contributions may range from financing nonproliferation research and education through social corporate responsibility programs to developing AI tools that help CBRN professionals tackle CBRN risks more effectively.

Well-designed AI applications can contribute significantly to CBRN risk mitigation. In the nuclear domain, for instance, AI could help enhance threat simulation, analysis, detection, and mitigation at civil nuclear facilities.10 As industry combines generative AI and computer vision for physical security applications, including by using LLMs to query surveillance footage11 and using AI-generated images and videos for the training of computer vision models for surveillance, there is potential for a significant upgrade of the physical protection capabilities of nuclear facilities.

In addition, generative AI is also being integrated into cybersecurity defenses.12 The IAEA is hopeful that “advanced machine learning algorithms” could help identify anomalous cyber activities and prompt the necessary response, despite lingering challenges in data availability and transparency regarding how algorithms arrive at particular outputs.13 When it comes to nuclear security, AI is a source of opportunities as much as it is a source of challenges.

Similarly, AI technology can enhance proliferation detection despite its potential contribution to proliferation risks. The U.S. National Nuclear Security Administration (NNSA), for instance, has used AI to monitor the “nuclear testing and proliferation activities” of U.S. adversaries for years and have continued to develop AI applications in this domain,14 including tools capable of discovering covert fissile material production and nuclear testing, identifying illicit procurement, and tracking technical research that may be useful for a weapons program.15 The Pacific Northwest National Laboratory and Sandia National Laboratories are developing a transformer-based model to detect anomalies in the process data from reprocessing facilities in order to alert IAEA safeguards inspectors about possible diversion.16 The IAEA, meanwhile, has recognized the potential for more advanced AI algorithms to enhance the review of safeguards surveillance footage, enabling earlier and more efficient detection of nuclear facility misuse and material diversion.17

Delegates to the COP29 Climate Conference in Baku, Azerbaijan, in November made progress discussing the global carbon market architecture, a governance model that could be applicable to AI in dealing with weapons of mass destruction risks. (Photo by Sean Gallup/Getty Images)

In the export control domain, the latest LLMs, with dramatically improved natural language processing and information retrieval capabilities, could overcome many previously identified limits of export control expert systems designed to advise on compliance.18 AI applications could be used to flag controlled items and investigate end users. They also could review unprecedented volumes of transaction records to identify anomalies, while multimodal LLMs capable of translating visual inputs into natural language could enhance the capacity of border and custom authorities to screen for sensitive items. Companies such as Toshiba already have begun implementing machine learning automated name matching to cross-check end users against export control lists to enhance compliance.19 Machine learning is also helping financial institutions detect illicit money transfers, thus preventing money laundering and terrorist financing, among other activities dangerous to the global community.20

The technologies for building more effective counterproliferation tools are already there. However, the incentive mechanisms that would reward private entities for operationalizing these technological benefits for international security are lacking or absent. In other words, the potential contribution of frontier AI technologies to the global societal good of CBRN security is underpriced. In this context, an offset scheme would reward AI companies for making such contributions while giving them an opportunity to balance out the global CBRN security costs that their innovation incurs, sometimes inevitably.

Multilateral Forums and International Organizations

The legally binding mandate already exists for states to tackle the threat of CBRN proliferation and terrorism by nonstate actors through domestic legislation and multilateral action. UN Security Council Resolution 1540 invokes Chapter VII of the UN Charter to direct that all states “shall adopt and enforce appropriate effective laws” to prohibit CBRN proliferation by nonstate actors “in particular for terrorist purposes, as well as attempts to engage in any of the foregoing activities, participate in them as an accomplice, assist or finance them.”

The same resolution calls upon states to take cooperative action against the threat of WMD proliferation by nonstate actors, including by developing “appropriate ways to work with and inform industry and the public regarding their obligations.” Going forward, state governments should affirm, inside and outside the working process of the 1540 Committee, that the resolution’s mandate extends to the mitigation of AI risks for WMD proliferation by nonstate actors. In addition, they should work toward establishing an incentive-based multilateral framework, supported by national legislation, to price in AI costs and benefits for global CBRN security.

Through further resolutions, the General Assembly could establish a group of governmental experts to develop a clear definition of AI-driven negative and positive externalities for CBRN security and study the feasibility of externality pricing and offset incentives for industry. The group could consider, for instance, ways of evaluating, if not quantifying, various frontier AI models’ contributions to CBRN risks. This exercise could lay the foundation for a global existential security tax or cap-and-trade system while paying particular attention to the impact of controls on developing countries’ equitable access to the peaceful uses of AI technology. The group also could consider implementation issues of a more technical nature, such as compliance monitoring.

International organizations such as the IAEA and the Comprehensive Test Ban Treaty Organization (CTBTO) are already eagerly exploring AI applications for the processing of safeguards and nuclear testing verification data.21 They should continue to leverage established internal mechanisms to operationalize these applications and consider formalizing existing working groups to form AI scientific advisory boards to keep pace with technological advancements. Private sector collaboration is indispensable in this regard. Governments should provide incentives such as tax credits to encourage AI companies to contribute novel solutions and expertise to augment the proliferation monitoring capacity of international organizations as well as the national enforcement of proliferation controls.

Finally, the next NPT Review Conference, in 2026, should consider ways of leveraging beneficial AI applications to further the treaty agenda. It could urge states to report their progress in introducing incentive schemes for regulating the AI industry’s global nuclear security and nonproliferation impact. The conference also could serve as a forum for developed and developing countries to deliberate upon the balance between global controls and equitable access to AI technologies.

In the new era of highly efficient frontier AI models, traditional state-centric CBRN controls are no longer sufficient to mitigate the risks associated with AI misuse by nonstate actors. By treating AI’s potential contribution to CBRN risks as a global negative externality, policymakers can leverage economics-based tools such as taxes, offsets, and club incentives to encourage responsible AI innovation.

Multilateral institutions must also adapt to this new reality by fostering collaboration with the private sector to integrate AI-driven solutions into their activities. Ultimately, the future of CBRN security depends on shaping the direction of AI innovation to balance its positive and negative externalities. A global incentive scheme is among the best ways to mobilize decisive actions before it is too late.

ENDNOTES

1. Sam Altman et al, “Governance of Superintelligence,” OpenAI, May 22, 2023.

2. OpenAI, “GPT-4 Technical Report,” OpenAI, March 2023.

3. Janet Egan and Eric Rosenbach, “Biosecurity in the Age of AI: What’s the Risk?” Belfer Center for Science and International Affairs, November 6, 2023.

4. Vienna Center for Disarmament and Non-Proliferation, “The Impact of Emerging Technologies on the Nuclear Supply Chain,” YouTube, January 17, 2025.

5. Peter Kaiser, “Can You Trust Your Newsfeed? New IAEA CRP Studies How to Mitigate the Harm of Misinformation in Nuclear Emergencies (J15001),” IAEA, January 29, 2019.

6. Jennifer Morris, “Carbon Pricing,” MIT Climate Portal, January 11, 2022.

7. Angelo Gurgel, “Carbon Offsets,” Climate Portal, November 8, 2022.

8. William Nordhaus, “Climate Clubs: Overcoming Free-Riding in International Climate Policy,” American Economic Review 105, No. 4, 2015, pp. 1339-70.

9. Siladitya Ray, “DeepSeek Rattles Tech Stocks: Chinese Startup’s Rise Against OpenAI Challenges U.S. AI Lead,” Forbes, January 27, 2025.

10. National Nuclear Security Administration, Prevent, Counter, and Respond—NNSA’s Plan to Reduce Global Nuclear Threats (Washington, DC: U.S. Department of Energy, 2023).

11. Ashesh Jain, “ChatGPT Meets Video Security: A New Era of Intelligent Surveillance,” Coram, October 30, 2023.

12. Eduard Kovacs, “ChatGPT Integrated into Cybersecurity Products as Industry Tests Its Capabilities,” Security Week, March 9, 2023.

13. Mitchell Hewes, “How Artificial Intelligence Will Change Information and Computer Security in the Nuclear World,” IAEA, June 2023.

14. Rick Perry, “Secretary Perry Addresses the National Security Commission on Artificial Intelligence,” U.S. Department of Energy, November 5, 2019.

15. National Nuclear Security Administration, Prevent, Counter, and Respond—NNSA’s Plan to Reduce Global Nuclear Threats.

16. Steven Ashby, “How PNNL Is Using Machine Learning to Detect Nuclear Threats Quicker and Easier,” Pacific Northwest National Laboratory, March 27, 2023.

17. H. Abdel-Khalik et al., Artificial Intelligence for Accelerating Nuclear Applications, Science and Technology (Vienna: International Atomic Energy Agency, 2022).

18. Rafal Rzepka, Daiki Shirafuji, and Akihiko Obayashi, “Limits and Challenges of Embedding-Based Question Answering in Export Control Expert System,” Procedia Computer Science No. 192, 2021, pp. 2709-19.

19. “Toshiba Strengthens Internal Export Control System with Babel Street Match,” Babel Street, accessed March 1, 2025.

20. Deloitte and United Overseas Bank, “The Case for Artificial Intelligence in Combating Money Laundering and Terrorist Financing,” Deloitte, accessed March 1, 2025.

21. “Science and Technology 2023 Conference: Scientific Advances in CTBT Monitoring and Verification,” CTBTO Preparatory Commission, June 2023.


Yanliang Pan is a research associate at the James Martin Center for Nonproliferation Studies. Daihan Cheng is pursuing a master’s degree in nonproliferation and terrorism studies at the Middlebury Institute of International Studies.

Although abandoned in 2024, the Korean Comprehensive Military Agreement served as a significant arms control measure when it was in effect.

April 2025
By Daeyeon Lee

Top leaders from North Korea and South Korea met in Pyongyang Sept. 19, 2018, to reduce tensions and build confidence on the Korean peninsula through the landmark Comprehensive Military Agreement (CMA). South Korean President Moon Jae-in and North Korean leader Kim Jong Un signed first, followed by their defense ministers. This deliberate sequence was proposed by South Korea to intentionally demonstrate the leaders’ commitment to the CMA, according to Choi Jong-kun, who was then South Korean secretary for peace and arms control.1

South Korean Defense Minister Song Young-moo (2nd L) and his North Korean counterpart, No Kwang Chol (2nd R), display the Comprehensive Military Agreement they signed in September 2018 at Paekhwawon State Guesthouse as South Korean President Moon Jae-in (L) and North Korean leader Kim Jong Un (R) look on. (Photo by Pyongyang Press Corps/Pool/Getty Images)

Previously, the two Koreas had signed 12 military agreements, none of which were ever implemented.2 In contrast, the CMA was put swiftly into action by both sides to manage security risks and build confidence across all border areas. Despite the collapse of the 2019 North Korean-U.S. summit in Hanoi, border stability largely persisted, although the diplomatic deadlock stalled further implementation of key CMA provisions.

Over time, the agreement deteriorated and was ultimately abandoned amid rising tensions over North Korea’s provocations and South Korea’s conservative shift. Its contributions to regional security were overshadowed as the focus turned toward South Korea’s nuclear ambitions, U.S. extended deterrence, and North Korea’s deepening military ties to Russia. Highly susceptible to shifts in U.S.-North Korea relations and South Korean domestic politics, the CMA’s trajectory was short-lived. Nevertheless, while in effect, it served as a significant arms control measure, alleviating tensions and fostering confidence between the two Koreas.

Origins of the CMA

In mid-2017, Moon took office, providing a measure of stability after President Park Geun-hye’s impeachment. However, nuclear tensions escalated as North Korea and the United States engaged in a war of words. In response to North Korea’s provocations, U.S. President Donald Trump warned of “fire and fury,” prompting Kim to threaten to strike Guam.3 When Pyongyang conducted its sixth nuclear test in September 2017, Trump vowed to completely destroy Pyongyang, leading North Korean Foreign Minister Ri Yong Ho to declare Trump’s statement a declaration of war.

As fears of nuclear conflict grew, Moon sought to de-escalate tensions, condemning North Korea’s provocations while vowing, “[t]here will not be a war again on the Korean peninsula.”4 Tensions escalated when Pyongyang tested a Hwasong-15 intercontinental ballistic missile November 29, 2017, declaring its “the state nuclear force” complete.5 Rather than taking countermeasures, Moon proposed suspending South Korea-U.S. military exercises during the 2018 Winter Olympics, a move the United States accepted. In response, North Korea halted provocations, participating in the Olympics and engaging in dialogue with Moon and Trump, briefly stabilizing the region.

Within three months of the CMA’s signing in September 2018, both sides demolished 22 guard posts in the Demilitarized Zone, disarmed the Joint Security Area, and ceased hostile acts across all border areas at sea, on land, and in the air.6 They halted artillery fire, and battalion-level field maneuvers, prohibited unannounced flights in the designated no-fly zone, and covered the barrels of naval and coastal guns and sealed them.

South Korean and North Korean army soldiers inspect a dismantled North Korean guard post inside the Demilitarized Zone in the inter-Korean border in Cheorwon, North Korea in December 2018. The demolition was mandated by the Comprehensive Military Agreement to reduce military tensions and build trust.  (Photo by Seung-il Ryu/NurPhoto via Getty Images)Although Kim’s diplomatic shift in 2018 helped facilitate the CMA’s implementation, the agreement itself played a critical role in avoiding escalation even when diplomacy stalled. According to South Korea’s 2022 defense white paper, Pyongyang violated the CMA twice between 2018 and 2022, with no significant rise in tensions.7 Beyond the de-escalation, the CMA improved South Korean security by significantly reducing North Korean infiltrations and local provocations, which previously had averaged more than 20 incidents per year but dropped to just one between 2018 and mid-2022.

The agreement also benefited civilians, particularly in the disputed Yellow Sea (West Sea) region, where past clashes in 1999 and 2002, the 2010 sinking of the Cheonan naval vessel, and the 2010 Yeonpyeong Island bombardment, had resulted in casualties and trauma.8 Following CMA implementation, the South Korean government expanded fishing hours for the first time since 1964 and extended fishing areas in 2019.9 By the CMA’s third anniversary, residents of the region experienced a period of peace and increased fish catches.

The Agreement Collapses

Progress toward further CMA implementation ceased after the 2019 Hanoi summit at which Kim and Trump failed to reach a nuclear deal. Kim offered to dismantle the Yongbyon nuclear facility and its nuclear weapons institute in exchange for partial UN sanctions relief, but Trump demanded the dismantlement of four additional nuclear facilities and full disclosure of North Korea’s weapons of mass destruction programs.10 When talks deadlocked, North Korea ignored Moon’s request to continue implementing CMA provisions, including further guard post demolitions, remaining excavations of war remains, and the formation of an Inter-Korean Military Committee.

The COVID-19 pandemic further deepened the impasse as North Korea closed its border in 2020. In mid-2022, South Korea’s conservative shift under President Yoon Suk Yeol hardened the country’s stance toward North Korea, which included advocating for a “preemptive strike” and “peace through strength.”11 During a visit to the DMZ in September 2023, Yoon ordered South Korean forces to retaliate against North Korea without hesitation if provoked.

On November 21, 2023, North Korea successfully launched a spy satellite after a few failures. The following day, Yoon suspended the CMA-established no-fly zone restrictions, which prohibit fixed-wing aircraft over the military demarcation line.12 Although the satellite launch violated UN sanctions, it had nothing to do with the CMA. The next day, North Korea announced that it would withdraw completely from the agreement.

Since then, tensions have escalated due to North Korea jamming South Korean GPS signals and its frequent artillery drills.13 South Korea has responded by expanding combined, joint military exercises with the United States and Japan. Finally, June 3, 2024, Yoon suspended the CMA after a series of North Korea-launched trash balloons that caused damage in South Korean cities.

Critics argue that the CMA was ineffective to begin with, weakening South Korean surveillance capabilities through the no-fly zone and allowing 3,600 cross-border violations.14 But the Moon administration has countered that, saying North Korea lacked medium-altitude and high-altitude reconnaissance aircraft and spy satellites, while the South, with U.S. support, maintains full surveillance over North Korean territory.15

Pedestrians walk past a video screen in Tokyo displaying the launch of North Korea's reconnaissance satellite 'Malligyong-1' on November 22, 2023.  (Photo by Kazuhiro Nogi/AFP via Getty Images)

Moreover, a South Korean civic group, People’s Solidarity for Participatory Democracy, filed an information disclosure request with the South Korean Defense Ministry to confirm the number of total CMA violations by North Korea. The ministry confirmed 17 such violations, including ground hostile action, artillery fire, and missile launches within the maritime buffer zone, and an airspace violation in the no-fly zone, along with 3,400 instances in which North Korea opened coastal artillery ports between November 2018 and October 2023.16 Significantly, these openings had not been counted as violations by the Moon administration, which considered them “facility management,” rather than serving an offensive purpose.17

Today, concerns over the likelihood of nuclear war on the Korean peninsula as a result of inadvertent conflicts between the two Koreas are growing again. In 2022, North Korea updated its nuclear doctrine, legalizing preemptive nuclear strikes to protect its leadership and nuclear command-and-control operations. In January 2024, Kim announced that North Korea is no longer seeking reunification because South Korea is the North’s primary adversary. Under these circumstances, if North Korea makes any misjudgment or miscalculation about South Korean military activities, it is more likely to use nuclear weapons to compensate for its relatively weak conventional forces. The risks of nuclear war are heightened in the absence of tension-reduction measures, such as the CMA.

Reactivation of the CMA

Trump’s return to the White House in January has added a new factor to geopolitics. He has expressed a willingness to engage China and Russia on nuclear arms control.18 His secretary of state, Marco Rubio, has emphasized the importance of reducing risks on the Korean peninsula to prevent inadvertent war. The administration also is seeking to revive direct engagement with Kim.19

As one step in achieving these objectives, the Trump administration should encourage Seoul to reactivate the CMA as a means of restarting and sustaining dialogue with Pyongyang. Although the North-South relationship is hostile, a progressive South Korean candidate, who condemned Yoon's suspension of the CMA last June and is pursuing reconciliation with Pyongyang, has a strong chance to succeed Yoon, once a court ruling on Yoon’s impeachment is decided in April.20

Under current circumstances, any inadvertent conflict on the Korean peninsula could lead to a confrontation, with the South Korean-U.S. alliance facing off against North Korea, backed by China and Russia. Even if North Korean-U.S. nuclear talks resume, North Korea’s threat perception of South Korea would remain. As a confidence-building and risk-reduction measure, the CMA has demonstrated that it can help manage risks on the Korean peninsula.

ENDNOTES

1. Jong-kun Choi, The Power of Peace, (Seoul: Medici Media, June 20, 2023), p. 103.

2. Ibid., KFN TV “2021 Defense Focus: The 3rd Anniversary of the September 19 Military Agreement, Its Significance and Achievements” YouTube, September 17, 2021.

3. Meghan Keneally, “From ‘Fire and Fury’ to ‘Rocket Man,’ the Various Barbs Traded Between Trump and Kim Jong Un,” ABC News, June 11, 2018, accessed September 1, 2024; “North Korea Calls Trump Tweet ‘a Declaration of War,’” CBS News, September 25, 2017, accessed September 1, 2024.

4. Alex Ward, “The President of South Korea Has a Strong Message for Trump,” Vox, August 17, 2017, accessed September 1, 2024.

5. Reuters, “North Korea Says New Missile Puts All of US in Striking Range,” BBC News, November 29, 2017, accessed September 19, 2024; Moon Jae-in, From the Periphery to the Center: Moon Jae In Memoirs of Foreign Affairs and Security, (Seoul: Gimmyoung, May 18, 2024), pp. 139-141.

6. Choi, The Power of Peace, pp. 111-114; Korea Policy Briefing, “September 19 Military Agreement,” accessed August 8, 2024.

7. South Korea Ministry of National Defense, “Defense White Paper 2020,” p. 393, accessed September 9, 2024, “Defense White Paper 2022,” p. 353, accessed September 9, 2024.

8. Andrew Yeo, “Inter-Korean Relations,” The National Committee on North Korea, September 2023, accessed September 19, 2024; Joseph S. Bermudez Jr., “The Yŏnp’yŏng-do Incident, November 23, 2010,” 38 North, January 11, 2011, accessed September 1, 2024.

9. KBS News, “West Sea Five Islands: Fishing Grounds Expanded by 84 Times Yeouido’s Size, Night Fishing Revived After 55 Years,” February 20, 2019, accessed September 19, 2024; KFN TV, “2021 Defense Focus: The 3rd Anniversary of the September 19 Military Agreement, Its Significance and Achievements,” YouTube, September 17, 2021.

10. Seigfried S. Hecker, Hinge Points: An Inside Look at North Korea’s Nuclear Program (Stanford University Press: January 10, 2023), pp. 338-340; Moon Jae-in, From the Periphery to the Center, p. 323.

11. Kim Mi-na and Kwon Hyuk-chul, “Yoon Says Preemptive Strike Is Only Answer to N. Korea’s Hypersonic Missiles,” Hankyoreh, January 12, 2022, accessed September 1, 2024; An Yong-su, “President Yoon Says, ‘If North Korea Provokes, Respond Without Waiting Even a Second’ [Comprehensive Report],” Yonhap News Agency, October 1, 2023, accessed September 1, 2024.

12. The National Committee on North Korea, “Agreement on the Implementation of the Historic Panmunjom Declaration in the Military Domain, signed by the Republic of Korea and the Democratic People’s Republic of Korea, September 19, 2018,” accessed September 1, 2024,; Soo-Hyang Choi, “North Korea Scraps Military Deal with South, Vows to Deploy New Weapons at Border,” Reuters, November 23, 2023, accessed September 1, 2024.

13. Won Hyung-min, “[Graphic] Recent North Korean Provocations and Suspension of the September 19 Military Agreement,” Yonhap News Agency, June 4, 2020, accessed September 1, 2024.

14. Frank Aum, “North Korea’s Satellite Launch Adds a Spark to Already Simmering Tensions,” United States Institute of Peace, November 27, 2023, accessed September 1, 2024; “Shin Won-sik: ‘North Korea Violated the 9/19 Agreement 3,600 Times…’ Suppressing Ambitions with ‘Powerful Force,’” Dong-A Ilbo, December 21, 2023, accessed September 1, 2024.

15. MBCNEWS, “‘Jukgangkkeut’ and ‘Great Change’ - The Chicken Game Between North and South Korean Hardliners), YouTube, January 7, 2024.

16. People’s Solidarity for Participatory Democracy, “[Statement] Withdraw the Suspension of the September 19 Military Agreement,” November 22, 2023, accessed September 1, 2024.

17. Kwon Hyuk-chul, “Five Years After the Buffer Zone Was Nullified… A Ticking Time Bomb in a South-North ‘Surveillance Contest’), Hankyoreh, accessed September 1, 2024; Josh Smith, “New North Korea Law Outlines Nuclear Arms Use, Including Preemptive Strikes,” Reuters, September 9, 2022, accessed September 1, 2024.

18. Arms Control Association, “ACA Welcomes Trump’s Acknowledgement of the ‘Tremendous’ Cost and Dangers of Nuclear Weapons and Interest in ‘Denuclearization’ with Russia and China,” January 24, 2025, accessed September 19, 2024; “Rubio Says He’ll Explore Ways to Lower Risks of ‘Inadvertent’ Inter-Korean War,” The Korea Times, January 16, 2025, accessed February 20, 2024.

19. Trevor Hunnicutt, “Exclusive: Trump Team Weighs Direct Talks with North Korea’s Kim in New Diplomatic Push, Sources Say,” Reuters, November 26, 2024, accessed February 20, 2024.

20. “Who Is Lee Jae-myung, South Korea’s Possible Next President?” The Economist, January 30, 2025, accessed January 30, 2024; Young-ho Kim, “Lee Jae-myung on the Suspension of the September 19 Military Agreement: ‘For Two Years, the Government Has Taken Out Its Anger on the North with Verbal Bombs’,” Kyeonggi Ilbo, June 5, 2024, accessed February 20, 2024; Da-sol Kim, “Yoon Suk Yeol’s Impeachment Verdict Could Be Pushed to April,The Korea Herald, March 26, 2025, accessed March 26, 2024.


Daeyeon Lee is an international security analyst specializing in nonproliferation and Korean security.

Ending the Nuclear Arms Race: A Physicist’s Quest
By Frank N. von Hippel

Hiroshima: The Last Witnesses
By M.G. Sheftall

April 2025

Ending the Nuclear Arms Race: A Physicist’s Quest
By Frank N. von Hippel
Lynne Rienner Publishers
2024

This book is a personal account of physicist Frank von Hippel’s decades-long efforts to reduce the risks of nuclear weapons. It starts with his early passion for physics, inspired by his grandfather’s role in the Manhattan Project. It then traces how the Vietnam War protests shaped his anti-nuclear beliefs, leading to his involvement in the Nuclear Freeze movement of the 1980s.

Von Hippel, a professor emeritus at Princeton University, is influential far beyond academia. He has advised multiple U.S. administrations in crises, spanning the Three Mile Island accident in 1979 to resolving the stalemate in negotiations with Iran on the Joint Comprehensive Plan of Action in 2015. The book also highlights his collaboration with Soviet leader Mikhail Gorbachev’s scientific advisers, which helped end nuclear testing and reduce U.S. and Soviet arsenals. What distinguishes this memoir is the delicate balance of technical specificity and accessibility. Von Hippel explains complex issues with precision and immersion that will likely engage both experts and regular citizens. The book is a timely reflection on the power of science and one man’s quest to affect nuclear policy outcomes, making it a must-read for anyone interested in nuclear matters.—DONIYOR MUTALOV



 

Hiroshima: The Last Witnesses
By M.G. Sheftall
Penguin Publishing Group
2024

This first installment of a two-volume series examines the events and aftermath of the U.S. atomic bombing of Hiroshima Aug. 6, 1945. Drawing from the author’s personal interviews and encounters, the book offers a deeply human perspective on the catastrophic consequences of nuclear warfare. It explores the limited understanding that U.S. military personnel had of the bomb and its devastating effects. The book also delves into Japan’s wartime kamikaze philosophy, tracing its roots in the samurai moral code of self-sacrifice to the suicide attacks by Japanese fighter pilots in World War II. The author explains how the United States underestimated this factor. By juxtaposing the present-day image of Hiroshima with its wartime legacy, he also critiques the longstanding “peace discourses” promoted by the Japanese and U.S. governments and explores the complexities of memory and reconciliation. Later chapters focus on poignant personal stories of the hibakusha—civilian survivors of the atomic bombing—and make their lesser-heard narratives accessible to English speakers. The harrowing tales of the hibakusha, as well as stories of those lost and injured in the bombings, speak for themselves. The book details the far-reaching consequences of nuclear weapons, from environmental destruction to humanitarian crises, and examines postwar Japan’s profound sociocultural and religious transformation. The second book, Nagasaki: The Last Witnesses, expected in 2025, will document the stories of hibakusha from Nagasaki. —SHAGHAYEGH CHRIS ROSTAMPOUR

April 2025
Reviewed by Kelsey Davenport

Sanctions for Nuclear Disarmament and Non-Proliferation: Moving Forward
By Armend Bekaj and Peter Wallensteen, eds.
Routledge Global Security Studies
2025

Making Sanctions More Effective

In the last several decades, sanctions have played a central role in international efforts to prevent the spread of nuclear weapons. Despite the increasing reliance on such unilateral and multilateral measures, their utility as a tool of statecraft in pressing nations to abandon nuclear weapons programs is largely unquestioned in policymaking circles. With a looming proliferation crisis on the horizon, fueled by territorial aggression and diminishing trust in alliances, sanctions will probably remain a key fixture in responding to the threat of new nuclear-armed states. But how effective are sanctions as a tool for preventing proliferation and promoting disarmament? How are they best integrated into broader strategies to prevent the spread of nuclear weapons?

Sanctions for Nuclear Disarmament and Non-Proliferation provides a critical and timely contribution to understanding the role of sanctions in disarmament and nonproliferation policy and to challenging established narratives about the utility of coercive measures in preventing the spread of nuclear weapons. The contributors deconstruct sanctions as a tool of statecraft and propose a working theoretical framework for employing and lifting sanctions. They also seek to discern how sanctions, and more specifically, certain types of sanctions, impact the target state’s decision to proliferate or disarm using case studies.

In deconstructing sanctions and providing a more nuanced approach to applying them, the book provides a much-needed evidence-based critique of the generalizations that frequently drive sanctions policy. The critique is more compelling in that it does not dismiss sanctions outright as a tool; it acknowledges the role that these coercive measures can play if properly calibrated and integrated into a broader strategy. The book does not consider sanctions in a vacuum but rather examines the necessity of rethinking the diplomatic frameworks and approaches in which sanctions operate, further contributing to the overarching policy relevance. Although this book is relevant to academics and policymakers, its arguments and conclusions are especially applicable for using sanctions more effectively for addressing contemporary proliferation challenges.

Positive and Negative Sanctions

One key contribution to policymaking is the discussion of the role that positive sanctions or inducements should play in nonproliferation and disarmament strategies. In contrast to negative sanctions, which are intended to punish or penalize, positive sanctions are additive, providing a benefit to the targeted state. Policymakers frequently dismiss positive sanctions as a sign of weakness or a reward for the targeted state, particularly if that state has not taken steps to reverse the activities that prompted sanctions.

These oil refineries and nuclear facilities could be prime targets if Israel or the United States decides to attack Iran.  (Photo by Efnan Ipsir/Anadolu via Getty Images)

David Cortright and Thomas Biersteker directly challenge that narrative in the chapter “Incentivizing Nonproliferation” and argue compellingly that positive sanctions pay dividends by creating opportunities for engagement and willingness to cooperate. Overreliance on negative sanctions, in contrast, isolates a state and can close off opportunities for interaction. The authors discredit the notion that negative sanctions alone will push the targeted state to change course. They suggest an integrative approach, which combines coercive sanctions targeted at decision-makers representing the offending state with focused engagement and incentives.

Cortright and Biersteker pay equal attention to the policy implications of relief from negative sanctions. In addition to providing a flexible framework for releasing pressure from negative sanctions in response to concessions from the targeted state, Cortright and Biersteker contend that inducements, such as investment guarantees, can supplement sanctions relief. The 2015 nuclear deal between Iran and six world powers highlights the importance of this point, where lifting sanctions alone did not provide the tangible economic benefits that Iran expected under the deal.

Although positive sanctions are rarely used today, the case study of West Germany by Dogukan Cansin Karakus illustrates the role that they can play. The author contends that the “multifaceted approach combining punitive actions with incentive-driven strategies” used by the United States influenced West Germany’s decision to join the nuclear Nonproliferation Treaty (NPT) in 1969. He further identifies that distinct characteristics shape a state’s decision-making and argues for a tailored strategy that considers a state’s ideology, security concerns, and economic imperatives in crafting an approach that balances positive and negative sanctions.

One theme that resonates through several chapters is the disconnect between perceptions of sanctions’ effectiveness and the impact of these measures on a targeted state’s behavior. George Lopez, for instance, calls attention to the outdated or erroneous generalizations about sanctions policy that still inform decision-makers, including the concept that noncompliance with sanctions should drive further sanctions imposition and that partial compliance by the targeted state suggests that holding firm on implementing sanctions will lead to 
full compliance.

Lopez presents a more accurate list of data-driven maxims for guiding sanctions policy, including the assessment that excessively punitive sanctions on broad sectors such as banking and trade are rarely successful and more often lead to the targeted state doubling down on its position rather than shifting its behavior. He argues that when a state employs sanctions without a strategy for engaging the targeted state it creates an environment in which sanctions become the strategy rather than a tool. He also posits that if sanctions are going to change a state’s behavior, it is most likely to happen in the first two and a half years of imposition.

Another policy-relevant contribution focuses on the importance of aligning sanctions action with a specific objective and clearly articulating that objective to the targeted state. The chapter on efforts to prevent proliferation in China and India by Rishika Chauhun offers a particularly useful breakdown for thinking about the relationship between sanctions and policy goals. Her approach to aligning sanctions to one of four key objectives offers a useful heuristic to policymakers who will pursue and assess sanctions effectiveness.

Chauhun’s framework states that sanctions can be used to demonstrate a response, deter future action, constrain a state from continuing a behavior, and coerce a state to improve its behavior. This approach of articulating specific nonproliferation objectives for sanctions is particularly relevant for U.S. policy. Increasingly, the United States has relied on overly broad sanctions measures and attempted to tie relief from those sanctions to the targeting state changing its behavior in multiple areas. Crafting targeted sanctions with more specific objectives could help policymakers better assess their effectiveness and better communicate their goals to the international community. It also would signal to the targeted state the concessions necessary to achieve sanctions relief.

Nuclear-weapon State Division

That observation is particularly relevant today, when unity among the five nuclear-weapon states recognized and bound by the NPT on prioritizing nonproliferation efforts is fracturing. As Lopez notes, shifts in the global economic system and the demise of the UN Security Council as “the major law-based structure with the authority and global support for imposing sanctions” negatively impact consistent sanctions use for nonproliferation policy. In recent years, for example, China and Russia have shielded North Korea from additional Security Council sanctions, despite blatant North Korean violations of UN restrictions on its nuclear program. Furthermore, the Trump administration’s decision to withdraw the United States from the 2015 nuclear deal with Iran in 2018, despite Tehran’s compliance, eroded the credibility of sanctions lifting. Policymakers will need to grapple with the implications of great- power disunity diminishing sanctions effectiveness as the world responds to proliferation threats.

A man in Jecheon, South Korea, enters the underground bunker he built to protect against a potential North Korean nuclear attack. Experts are concerned that Saudi Arabia, South Korea, and Turkey could someday become the next nuclear-weapon states. (Photo by Anthony Wallace / AFP via Getty Images)

The shifting proliferation environment and the emergence of nuclear weapons discourse in states that are U.S. allies or partners suggests that Washington will need to grapple with contradictions between pursuing national security and prioritizing nonproliferation. In a chapter focused on Pakistan, Bekaj and Chihaun review how U.S. security interests in Pakistan clashed at times with sanctions targeted at Pakistan’s nuclear weapons program. The authors describe the U.S. approach to stymieing Pakistan’s nuclear weapons ambitions as “erratic and dysfunctional” and the implementation of sanctions relegated to a less important role compared with the country’s geostrategic value. Pakistan’s relationship with China, and Beijing’s willingness to assist at certain periods, led the authors to conclude that the threat of sanctions and the ability of the international community to lift sanctions were credible only when there was international consensus.

The lessons drawn from the Pakistan case are particularly relevant when considering the U.S. response to possible future proliferators. Apart from Iran, current proliferation threats include Saudi Arabia, South Korea, and Turkey. In these cases, geostrategic interests could be competing with nonproliferation norms, possibly impacting the extent to which the sanctioning state would enforce negative sanctions targeting nonproliferation. This dynamic underscores the necessity of rethinking positive sanctions and of integrating inducements into nonproliferation strategies.

In addition to its utility in challenging predominant narratives that portray sanctions as a panacea, the book raises important questions for further research that could positively influence how sanctions are used in statecraft. While arguing that positive sanctions should be a more integrated part of nonproliferation policy, the authors acknowledge that more research on such inducements and the sequencing of positive and negative sanctions is necessary. They point out that security guarantees and alliances historically have served as important inducements, but the shifting geopolitical landscape has diminished the credibility of security commitments. Without addressing the security drivers of proliferation, states will be less likely to reverse nuclear weapons programs. The United States, in particular, will need to examine the consequences for proliferation that could emerge from rolling back extended deterrence commitments and questioning the value of alliances.

Another area that could be ripe for further study is the potential role of nuclear cooperation—in areas such as energy generation, medicine, and agriculture—as a positive sanction. In addition to providing direct benefits to the state, positive sanctions in the peaceful nuclear cooperative space would build additional transparency around nuclear programs and foster ties between expert communities that could be used to clarify intentions.

As well as highlighting the gaps between the perceived and actual effectiveness of sanctions, the book provides new, compelling guidelines for the use of sanctions in a more integrative strategy. Dispelling deeply held beliefs by policymakers, particularly in the United States, however, will be challenging.

With multiple proliferation threats looming, nonproliferation policy will remain a critical issue for years to come. This book is an indispensable contribution to rethinking how sanctions are applied and framed to prevent the spread of nuclear weapons.


Kelsey Davenport is the director for nonproliferation policy for the Arms Control Association.

Rogov was a leading Russian and international specialist on arms control.

April 2025
By Alexey Gromyko

Sergey Rogov was born in Moscow in 1948. His father was a Soviet Air Forces officer. His mother taught history at school. As a result, military history became the passion of his life. It helped him grow into one of the leading Russian and international specialists on arms control.

Photo credit: Council of the Federal Assembly of Russia

Rogov spent his childhood in military towns and from his earliest days was obsessed with military maps, from the campaigns of Alexander the Great to World War II. When he was six years old, his family moved to Siberia where they lived near the Belaya Long-Range Aviation Base. There, Rogov endured daily five-kilometer walks to school, including in winter when temperatures of minus 40 degrees Celsius were not unique. Such hardship only contributed to the strength of his character. Later, when his family returned to Moscow, Rogov finished school with a gold medal and went to a famous state institute of international relations in Moscow.

His life took a definite turn in 1971 when he joined the Institute for U.S. and Canadian Studies (ISKRAN) at the Russian Academy of Sciences. The head of ISKRAN was Georgy Arbatov, who was for many years a key figure in relations between the Soviet Union and the West. Arbatov was on a good footing with Soviet Foreign Minister Andrey Gromyko and the institute enjoyed special treatment: the right to send one of its researchers to the Soviet Embassy in Washington with the rank of first secretary, and to send two interns to the Soviet Mission to the United Nations.

In 1973, Rogov became one of the interns. He lived in a small, rented flat on 96th Street in Manhattan. It did not escape his attention that time and again, judging by the burned butts of expensive cigarettes, the FBI visited the flat in his absence. Even more curious, a bottle of Stolichnaya in the refrigerator also was taken into consideration by the FBI visitors, who would add water to it. One time, Rogov put a sticker on the front door: “Drink vodka but after, don’t add water.”

Professionally, it was a happy time; he stayed in New York for a year and a half, establishing many contacts, some of whom lasted for the rest of his life. In 1984, as more mature specialist, Rogov was appointed an ISKRAN representative at the Soviet Embassy in Washington. He replaced Valentin Berezhkov, who had translated for Joseph Stalin. Earlier that year, Rogov defended his doctoral thesis on the political-military alliance between the United States and Israel.

It was not a coincidence that later, in the twilight of the Soviet Union, Rogov went to Israel for meetings. One morning at 8 a.m., he knocked at the door of the Israeli Labor party headquarters. Gen. Yitzhak Rabin, with whom he had an appointment, let him in. Rogov, who wore a suit, was taken off guard by Rabin’s appearance: barefooted and in a shirt. They started a conversation that led to the issue of an Israeli-Palestinian peace treaty. The general’s face, according to Rogov’s reminiscences, turned querulous. But the Russian was well-armed and put a bottle of Moskovskaya vodka on the table. Rabin’s eyes became animated. Rogov argued that it was possible to strike a peace deal with Palestinian leader Yasser Arafat and Rabin insisted that “with that terrorist,” he would never have anything in common. Before 9 a.m., the bottle was empty. Two years later, Rabin signed the Oslo accords.

In 1995, Rogov was elected director of ISKRAN, replacing Arbatov and remaining until 2015. From the 1970s through the 1990s, Arbatov and Rogov created a dense fabric of professional and personal contacts with U.S. experts, diplomats, and politicians. Rogov was unmatched in arranging confidential discussions, dialogues, and Track II meetings. In the course of this tireless activity, he built a reputation as a tough negotiator and a trusted friend. His counterparts included secretaries of defense Robert McNamara, Les Aspin, and William Perry; secretaries of state Henry Kissinger and Condoleezza Rice; national security advisors Brent Scowcroft and Zbigniew Brzezinski; and senators Sam Nunn and Richard Lugar.

One recent Rogov success was staging the Russian-American Conference on Arms Control in Moscow in April 2019. He co-organized previous events in this series with the Arms Control Association, the Deep Cuts Commission, and the Nuclear Crisis Group. At the 2019 conference, Rogov was behind a public statement by U.S. and Russian experts urging the United States and Russia to resume arms control negotiations, especially on the New Strategic Arms Reduction Treaty. Among his other achievements were the dialogue on military risk reduction in Europe, launched with the Institute of Europe in 2020, and co-moderating seminars with the Committee on International Security and Arms Control.

Once, I was standing with Sergey at the viewing point on the notorious, yet heroic Seelow Heights over the Oder River. In April 1945, a bloody battle played out there as Soviet troops approached Berlin and many thousands of them sacrificed their lives in the muddy terrain. As we looked down the plain before us, I noticed tears in Sergey’s eyes. I never asked him if it was wind. He dedicated his life to arms control and his credo was straightforward: Arms are inevitable; control is existential.

French President Emmanuel Macron said he would open a strategic debate with allies on the role of French nuclear forces in their protection.   

April 2025
By Xiaodon Liang

Leaders in France, Germany, and Poland have signaled plans to fundamentally reconsider their countries’ nuclear policies as Europe adjusts to the possibility of weaker U.S. commitments to the continent under a second Donald Trump presidency.

In a March 5 televised address, French President Emmanuel Macron said he would open a strategic debate with European allies on the role of French nuclear forces in their protection. Macron made a similar offer to discuss France’s notably opaque nuclear policies to allies in February

French President Emmanuel Macron, shown during a live interview on French TV, announced March 5 plans for a meeting of countries ready to guarantee a future peace in Ukraine. (Photo by Ludovic Marin/AFP via Getty Images)

 2020, when he declared that “France’s vital interests now have a European dimension.” (See ACT, March 2020.)

The suggestion of a greater role for French nuclear forces in defending against a perceived Russian threat comes at the invitation of German Chancellor-elect Friedrich Merz, who, speaking Feb. 21 to German television station ZDF, said Germany should discuss how French and UK nuclear forces could help guarantee European security.

Merz also called for a new European nuclear sharing arrangement, but clarified in a March 9 radio interview that he would prefer to see existing NATO nuclear sharing plans, which call for NATO aircraft to deliver U.S. gravity bombs stationed in Germany and four other NATO countries, maintained as well.

Nuclear sharing was not mentioned in Macron’s March 5 speech. The president made clear instead that nuclear decisions would remain in his hands.

In a March 6 radio interview, French Defense Minister Sébastien Lecornu affirmed that sharing French nuclear forces was not part of Macron’s offer.

Merz also emphasized that Germany would not seek nuclear weapons itself due to its treaty obligations.

The incoming chancellor has made German rearmament a priority. On March 18, the Bundestag, in a lame-duck session, approved a package of amendments to Germany’s Basic Law that would permit a significant increase in military spending.

Polish Prime Minister Donald Tusk also signaled his intention to engage Macron on the offer of a French nuclear umbrella in a March 7 speech to the Polish parliament. Tusk suggested that Poland should “reach for opportunities related to nuclear weapons,” according to The New York Times, although he paused short of calling for a national nuclear weapons program.

Polish President Andrzej Duda, a political rival of Tusk, renewed March 13 his call for the United States to deploy nuclear weapons in Poland as part of NATO’s nuclear sharing arrangements. Duda, who faces reelection in May, made a similar pitch to the Biden administration in 2022. (See ACT, November 2022.)

U.S. Vice President J.D. Vance was quick to dismiss the prospect, saying in a Fox News interview on the same day that he would be “shocked” if President Donald Trump would support the idea.

Macron’s extended deterrence proposal has been met with a mixture of concern and scorn in Russia. Kremlin spokesman Dmitry Peskov accused the French president of “thinking more about war, about continuing the [Ukraine] war,” in March 6 comments to reporters.

But Russian Foreign Minister Sergey Lavrov made light of the French offer in a March 12 interview, describing it as a pledge to “protect all of you with my three or four nuclear bombs.”

The United Kingdom did not respond in public to Merz’s call for new dialogue on European extended deterrence. Unlike France, the UK already maintains that its nuclear forces are assigned to defend the NATO alliance.

The UK government believes that U.S. technical support for UK nuclear forces continues to be reliable, according to a comment by the prime minister’s office to The Guardian. The statement came after a former UK ambassador to the United States, David Manning, questioned the longstanding nuclear relationship in March 5 testimony before a House of Lords committee.

The renewed push across Europe for increased military spending comes after signals that U.S. commitments to NATO’s defense might be weakening. A confrontational Feb. 13 speech by Vance at the Munich Security Conference inflamed concerns initially prompted by the U.S. administration’s direct outreach to Russia on the war in Ukraine.

“Listening to that speech, they try to pick a fight with us and we don’t want to pick a fight with our friends,” said Kaja Kallas, the European Union’s high representative for foreign affairs, on Feb. 14, Reuters reported.

Trump further exacerbated European worries March 6 when he said that the United States might adopt a policy of not defending NATO allies that fail to meet military spending targets. “If they don’t pay, I’m not going to defend them,” he said, according to the Associated Press. The comment came after NBC News first reported on the potential policy shift, citing multiple administration sources.

Leaders of the 27 EU member states endorsed on the same day a proposal by the European Commission to ease the bloc’s budgetary spending rules to permit additional military spending. Commission President Ursula von der Leyen claimed that this would allow for about $700 billion in additional military investment, which could be supplemented by another $160 billion in EU-backed loans.