Dmytro YEFREMOV, PhD in Economics, the Board Member of the Ukrainian Association of Sinologists

Acknowledgements

This policy comment is based on ideas and perspectives expressed during the roundtable discussion by international experts Nickolas Roth (Senior Director of the Nuclear Treat Initiative’s Nuclear Materials Security program), Mariana Budjeryn (Senior Research Associate at Harvard Kennedy School Belfer Center), Pan Yanliang (Research Associate at the James Martin Center for Nonproliferation Studies, Middlebury Institute of International Studies, Monterey), Lily Wojtowicz (Research Fellow, Centre for International Security, Hertie School, Berlin), and Kaiser Kuo (moderator, Sinica Podcast). 

Executive summary

• Russia’s nuclear posturing in the Ukraine war has elevated the risks of both strategic and civilian nuclear crises. Through threats, deployments to Belarus, and weaponization of the Zaporizhzhia Nuclear Power Plant, Moscow has challenged Western deterrence and weakened arms control norms, while exploiting delays in NATO support to constrain Ukraine’s defense options.
• The International Atomic Energy Agency faces severe constraints in managing nuclear security amid active conflict. Despite monitoring efforts, it lacks enforcement authority, while geopolitical rivalries—especially involving Russia and China—undermine cooperative nuclear governance and risk non-proliferation backsliding.
• S.–China nuclear divergence further destabilizes the global order. With Washington clinging to Cold War-era deterrence and Beijing pursuing conditional restraint, Ukraine’s denuclearization experience highlights the failure of current security assurances and the urgent need for credible, institutionalized nuclear risk reduction.

1. Russia’s Nuclear Posturing and Its Strategic Impact on the War in Ukraine

The Issue. Russia’s full-scale invasion of Ukraine has profoundly escalated nuclear safety risks across Europe. Moscow’s nuclear signaling, including explicit threats of tactical nuclear use, forward deployment of nuclear assets to Belarus, and the instrumentalization of nuclear rhetoric, has raised the stakes of escalation. Beyond military deterrence dynamics, Russia’s seizure of the Zaporizhzhia Nuclear Power Plant (ZNPP) has introduced an unprecedented risk of radiological disaster in a war zone. NATO hesitation in providing certain weapons systems reflects the effectiveness of Russian nuclear blackmail, even as Ukrainians themselves remain undeterred. Simultaneously, the erosion of arms control regimes, U.S. missile defense expansion plans, and China’s rapid arsenal growth amplify systemic risks. The central question today is: What are the most significant nuclear safety risks for Ukraine?

Analysis. Russia has deliberately escalated its conventional war into a nuclear-tinged crisis. As Budjeryn notes, while nuclear deterrence between great powers remains a structural feature of the international system, President Putin’s frequent nuclear threats exceed traditional doctrine. These signals appear designed to influence Western decision-making, particularly by discouraging the supply of advanced weapons like ATACMS or long-range missile systems to Ukraine. Although only partially successful, such rhetoric has introduced delays and constraints, ultimately reducing Ukraine’s battlefield options. Importantly, Ukrainians themselves have not been deterred—their fight remains existential. Yet the hesitation of Western states reveals that Russia’s nuclear signaling has had a deterrent effect, emboldening Moscow’s broader aggression.

Roth has warned that we are now in one of the most precarious nuclear moments since the Cold War. Russian threats have eroded established norms and emboldened military behavior, even though the invasion has damaged Russia strategically. Crucially, Roth underscores that civilian nuclear risks—such as those surrounding the ZNPP—are inseparable from military deterrence, forming part of a wider spectrum of radiological threats.

Budjeryn also stresses that the risk of actual nuclear use cannot be dismissed. While classical deterrence theory assumes rational cost-benefit calculations, escalation might still occur if Russia seeks to prevent defeat or force Ukraine into surrender. She suggests this could echo the U.S. use of nuclear weapons in 1945 as a mechanism to end war. Wojtowicz, while skeptical of this analogy due to the historical uniqueness of U.S. nuclear monopoly, acknowledges that there is precedent for contemplating nuclear use to secure battlefield advantage. This raises the disturbing possibility of a tactical nuclear strike against a Ukrainian city or military asset, showing that even the threat of nuclear force can constrain democratic decision-making.

The broader erosion of arms control compounds these dangers. Russia’s suspension of New START and withdrawal from the Comprehensive Nuclear-Test-Ban Treaty, alongside U.S. plans for space-based missile defense systems like the “Golden Dome,” destabilize strategic calculations. Roth notes that current debates prioritize technical feasibility over strategic restraint, increasing the risk of unregulated nuclear competition and crisis instability—especially in Europe.

Pan emphasized China’s categorical “no first use” policy, which contrasts with Russia’s nuclear coercion. Since 1964, Beijing has positioned its arsenal as a minimal deterrent rather than a warfighting tool. However, China’s arsenal expansion—from around 200 warheads two decades ago to over 600 today according to unclassified estimates—signals its concern about U.S. missile defense developments. Pan noted that minimal deterrence under conditions of expanding U.S. defenses requires larger arsenals. The opacity of China’s doctrine complicates global stability, especially since its command-and-control systems may be less mature than those of the U.S. or Russia. Importantly, Pan argued that U.S.-China nuclear risk reduction talks should prioritize technical safeguards—fail-safes, pre-notification of tests, and safety exchanges—to avoid accidental war.

China’s position is significant for Ukraine: while Beijing is unlikely to condone Russian first use, its growing arsenal and wary stance toward U.S. defenses shape the broader deterrence environment in which Ukraine’s security is embedded.

Wojtowicz examined Russia’s forward deployment of nuclear systems to Belarus. She argued that in geographic terms, it does not dramatically shift the threat for Berlin or Warsaw, but politically it reinforces Russia’s tit-for-tat posture and heightens NATO’s debates on nuclear sharing and burden distribution. While Cold War debates feared nuclear-sharing arrangements could lead to proliferation, Wojtowicz noted that Russia’s control of Belarusian-deployed systems will remain absolute, eliminating any real risk of “rogue” Belarusian control. Still, the deployments compress decision-making timelines for NATO and erode European publics’ sense of security.

2. The IAEA’s Constraints amid Russia’s Militarization of Civilian Nuclear Facilities in Ukraine

The Issue. The unprecedented occupation of civilian nuclear facilities, particularly the Zaporizhzhia Nuclear Power Plant, has exposed limitations in the International Atomic Energy Agency’s (IAEA) mandate and operational capacity. The IAEA, under Director General Rafael Grossi, seems to have played an important role in Ukraine by outlining the Seven Indispensable Pillars and Five Concrete Principles of nuclear safety and helping the Board of Governors adopt resolutions condemning Russia’s actions. Beyond diplomacy, the Agency activated its Incident and Emergency Centre at the start of the war, carried out some on-site missions, delivered safety equipment, and provided technical assistance. These steps suggest the DG has been able to advance the IAEA’s mission to some extent, yet their lasting impact is uncertain in the face of great-power divisions — a reminder that the effectiveness of international institutions in protecting Ukraine’s nuclear facilities must be judged against both the realities of war and the broader erosion of cooperative nuclear governance.

Analysis.  Russia’s seizure of ZNPP was initially chaotic and unplanned, but soon evolved into a deliberate strategy, as Budjeryn noted. The facility was transformed into a military shield and staging ground, with Russian forces exploiting Ukraine’s reluctance to strike a nuclear site. This militarization introduced unprecedented risks: firefights within the plant perimeter, repeated loss of off-site power critical for reactor safety, and military equipment stored in sensitive areas.

While the IAEA, under Director General Rafael Grossi, has been proactive, its mandate is inadequate for wartime conditions. The agency has conducted inspections, reported on safety breaches, and kept global attention focused on the dangers, but it lacks enforcement tools. Its authority rests on member-state cooperation, which Russia—holding veto power in the UN Security Council and significant influence within nuclear governance forums—has undermined. The Ukrainian case reveals that existing norms, including prohibitions under the 1977 Additional Protocol I to the Geneva Conventions, are insufficient when a nuclear-armed aggressor deliberately disregards them.

China is alarmed by the breakdown of security assurances and the perception that nuclear-armed states can exploit their arsenals to make political threats, as Pan noted. This perception undermines non-proliferation norms, potentially incentivizing states, heavily reliant on nuclear power and facing security threats, to seek stronger deterrents, whether through indigenous nuclear programs or enhanced alliances. For international institutions like the IAEA, the challenge lies less in Chinese ambivalence than in broader geopolitical and financial uncertainties: China has actively supported the Agency’s technical assistance to Ukraine, while recent U.S. policy shifts have introduced questions about the stability of funding for international organizations.

Initially, Russia’s invasion and occupation of nuclear facilities galvanized support for defense spending and cooperation within NATO, as Wojtowicz highlighted. However, as the war has dragged on, enthusiasm has waned, and nuclear deterrence remains deeply unpopular in societies such as Germany’s. This creates a paradox for international institutions: while governments recognize the urgency of reinforcing nuclear safety mechanisms, their domestic constituencies are reluctant to support measures perceived as escalating nuclear entanglement. For the IAEA, which depends on financial contributions and political backing, this tension translates into limited resources and uneven political support for bold action.

The human dimension of nuclear security during wartime is equally important, Budjeryn emphasized. Ukrainian engineers at ZNPP faced impossible choices: abandon their posts and risk a meltdown, or remain under occupation, risking their lives and families. The IAEA has reported on safety standards, but it has little ability to address the moral and psychological dilemmas of staff forced to maintain reactors under duress. This underscores a gap in the global nuclear governance framework: institutions are designed for technical oversight and treaty compliance, not for managing the human consequences of armed occupation. As such, nuclear security in Ukraine has become not only a technical and political issue but also an ethical one, demanding a rethinking of resilience and contingency planning for nuclear energy in conflict zones.

The effectiveness of international institutions cannot be separated from the broader geopolitical environment. Russia’s willingness to disregard international norms makes enforcement mechanisms toothless, while its veto power prevents the UN from mandating stronger action. The U.S. and European powers have supported the IAEA but remain constrained by fears of escalation and by domestic political limits. China, though nominally supportive of non-use norms, prioritizes its strategic rivalry with Washington over proactive involvement in Ukraine’s nuclear safety. North Korea’s military support for Russia, mentioned by Roth, further complicates the picture by tying the European theater to proliferation challenges in Asia.

In this context, international institutions have been effective only in a limited sense: they have documented violations, kept nuclear safety on the global agenda, and provided a platform for dialogue. But they have not been able to prevent the militarization of nuclear sites, ensure safety against repeated disruptions, or enforce compliance with international law. Their role has been reactive and constrained, rather than preventive and decisive.

3. U.S.–China Deterrence Divergence and the Future of Strategic Stability

The Issue. The war in Ukraine has reinvigorated debates about nuclear deterrence, arms control, and security assurances, exposing stark contrasts between U.S. and Chinese approaches. Washington remains tied to Cold War legacies of deterrence, alliance-based nuclear sharing, and an erosion of arms control treaties. Beijing, meanwhile, insists on minimum deterrence and conditional restraint, refusing arms reductions until reaching parity with the United States and Russia. At the same time, Ukraine’s experience as a denuclearized state under weak security assurances raises urgent questions about the credibility of guarantees offered by nuclear powers. The clash between U.S. and Chinese positions is not simply technical—it reflects competing strategic cultures, divergent views toward the role of nuclear weapons and deterrence. Understanding these differences is essential for reducing nuclear risks amid an unstable European security environment.

Analysis. Under inconsistent figures like Donald Trump, American nuclear signaling can appear as “a threat that leaves everything to chance,” as for Roth’s opinion. Such unpredictability undermines deterrence credibility and complicates arms control dialogue. The collapse of key treaties—INF, the suspension of New START, the ABM Treaty—is evidence that the traditional arms control framework has eroded. Practical confidence-building measures such as reaffirming test and production moratoria, weapons-grade fissile material stockpile reduction, limiting provocative exercises, and strengthening crisis communication mechanisms. These steps would reduce risks, but their implementation requires political will that is currently absent.

Wojtowicz expanded on this, stressing the atrophy of communication channels between the U.S. and Russia, which once underpinned stability even during moments of confrontation. Trump’s transactional approach and inconsistency make it unlikely that such channels will be reestablished soon. Years of effort to align allies on the China challenge were undermined by Trump’s erratic diplomacy, tariffs, and unilateral decisions. The danger is that U.S. nuclear commitments—whether in Europe or Asia—become unreliable in the eyes of allies and adversaries alike. In Ukraine’s case, this could mean Washington strikes deals that exclude Kyiv, leaving it to bear the consequences.

Pan shed light on the Chinese position, which promotes the no-first-use principle and negative security assurances. China has avoided naming and shaming Russia as Western countries do, but its perspective resonates with many non-nuclear-weapon states that see hypocrisy in both U.S. and Russian behavior—denouncing proliferation while modernizing arsenals and engaging in nuclear sharing and extended deterrence. Both have used deterrence coercively and refused to renounce nuclear first use in practice. While Beijing maintains agreements with Moscow on launch notification, it is unlikely to sign similar agreements with Washington. Nor is substantive agreement on arms reduction likely until greater parity is reached. China views U.S. missile defense deployments and modernization plans as destabilizing, and it perceives American support for Israeli counterproliferation strikes as evidence that Washington, like Moscow, does not qualify as a “responsible” nuclear actor. For Beijing, arms control is not a matter of abstract norms but of relative power and security interests.

Budjeryn drew attention to Ukraine’s unique nuclear history, noting how contemporary narratives oversimplify the choices made in the 1990s. In Ukrainian public discourse today, the decision to relinquish the world’s third-largest nuclear arsenal is often portrayed as a catastrophic mistake, a surrender “for nothing.” The historical reality was more complex: Ukraine inherited Soviet weapons but lacked an independent deterrent, and the global zeitgeist of the early 1990s favored disarmament and cooperation. Nonetheless, Ukraine’s experience demonstrates the weakness of security assurances absent binding guarantees. The Budapest Memorandum failed to prevent Russian aggression, leaving Ukrainians skeptical of great power promises. This history undermines the credibility of future assurance regimes, whether in Europe or elsewhere, unless underpinned by robust institutional frameworks.

Taken together, the U.S. and Chinese positions diverge not only in policy but in philosophy. The U.S. continues to rely on forward-deployed deterrence, extended guarantees to allies, and weapons modernization. China insists on minimum deterrence, rejects premature reductions, and frames itself as renouncing nuclear coercion. For Ukraine, caught between these competing logics, the lesson is grim: neither the U.S. model of assurances nor China’s rhetoric of restraint has produced real security. As Budjeryn emphasized, Ukraine’s compliance with international norms has not prevented it from becoming a victim of aggression, exposing systemic flaws in the nuclear order.

Policy Recommendations

• Western governments should develop a unified strategy for Ukraine that addresses both the risks of nuclear escalation and the safety and security of civilian nuclear facilities, while also sustaining arms control guardrails and removing incentives for Russia’s nuclear coercion to succeed.
• International institutions must strengthen their mandates to address nuclear security in active conflicts by integrating enforcement mechanisms, contingency planning for occupied facilities, and renewed great-power commitments to insulate nuclear safety and security from geopolitical rivalry.
• The United States and China should initiate a structured, incremental dialogue on nuclear risk reduction—focused first on communication mechanisms and mutual restraint in Ukraine-related contexts—while coupling it with a multilateral effort to reexamine the credibility of security assurances for non-nuclear states.

This policy comment is the result of the first open discussion initiated by the Center for Slavic, Eurasian, and East European Studies (CSEEES) at the University of North Carolina at Chapel Hill, held on the Ukrainian Platform for Contemporary China. The event was co-organized in partnership with the Sinica Podcast, the Ukrainian Association of Sinologists, and the A. Krymskyi Institute of Oriental Studies at the National Academy of Sciences of Ukraine.