Abstract
This article advances a policy-oriented argument about the legitimacy and sustainability of nuclear deterrence in light of the expanding scientific and humanitarian evidence base on the consequences and risks of nuclear weapons. Drawing on research developed through the Humanitarian Impacts of Nuclear Weapons Initiative and on arguments elaborated within the Treaty on the Prohibition of Nuclear Weapons (TPNW), particularly the 2025 report on the security concerns of states parties under the TPNW, the article argues that contemporary knowledge about nuclear weapons consequences has shifted the terms of the nuclear deterrence debate for non-nuclear states. From this perspective, the central problem is no longer only whether nuclear deterrence can be defended as a strategic doctrine, but whether it remains politically, legally and ethically legitimate when assessed against evidence of catastrophic humanitarian harm, environmental disruption, food insecurity, health-system collapse, transboundary effects and systemic global risk. The article synthesizes existing scientific, legal and policy literature to articulate a critical perspective on nuclear deterrence and to promote policy arguments developed in the TPNW framework that articulate the security perspective of states not relying on nuclear weapons. It contends that the nuclear deterrence discourse has not adequately absorbed the implications of humanitarian evidence and nuclear risk research, creating an asymmetry between what is empirically known about nuclear consequences and what is assumed about nuclear deterrence stability. The article concludes that nuclear security debates must be rebalanced by integrating humanitarian evidence, security concerns of non-nuclear-weapon states and risk-based arguments into mainstream policy deliberation.
1 Introduction: a perspective and policy intervention
Eighty years after the atomic bombings of Hiroshima and Nagasaki, nuclear weapons remain central to the security doctrines of nuclear-armed states and many of their allies. The contemporary moment is characterized by stagnation on arms control and nuclear disarmament, regression, polarization, and renewed reliance on nuclear deterrence amid heightened geopolitical tensions. Arms control agreements have eroded or collapsed, nuclear modernization programs are advancing across all nuclear-weapon states, and nuclear rhetoric has re-entered mainstream strategic discourse with alarming regularity. At the same time, the political and evidentiary context in which nuclear deterrence is defended has changed significantly. The past two decades have seen a major expansion of scientific research on the humanitarian, environmental, climatic, medical, developmental and systemic consequences and risks of nuclear weapons. This research has deepened the understanding of nuclear use beyond blast, heat and immediate radiation effects. It has shown how nuclear detonations could trigger regional and global consequences such as climate disruption, famine, marine and agricultural collapse, severe public-health breakdown, forced displacement, long-term genetic and environmental harm and cascading economic and political instability (, ; ; Xia et al., 2022; ).
The Treaty on the Non-Proliferation of Nuclear Weapons (NPT) long regarded as the cornerstone of the global nuclear order, is under visible strain with deep divisions between nuclear-weapon states (NWS) and non-nuclear-weapon states over the pace and sincerity of disarmament efforts. While the NPT rests on a foundational bargain—non-proliferation commitments in exchange for nuclear disarmament progress and access to peaceful nuclear technology—many non-nuclear-weapon states perceive an imbalance between obligation and implementation. The modernization of nuclear arsenals (), doctrinal expansions, and reaffirmations of nuclear deterrence reliance have reinforced perceptions that nuclear weapons are being normalized rather than marginalized.
Against this backdrop, the Treaty on the Prohibition of Nuclear Weapons (TPNW) has emerged as both a normative and legal development reflecting profound dissatisfaction with the status quo. Rooted in humanitarian considerations and recent scientific evidence about the consequences and risks of nuclear weapons and supported predominantly by non-nuclear-weapon states, the TPNW codifies an alternative security perspective: one that defines nuclear weapons primarily as instruments of unacceptable humanitarian harm rather than as guarantors of security and strategic stability (). The treaty's proponents argue (TPNW Declaration Third Meeting of States Parties) that the catastrophic consequences of nuclear weapon use—whether intentional or accidental—render them incompatible with the principles of international humanitarian law and responsible security policy.
The purpose of this article is to serve as a perspective piece and policy intervention from someone closely involved in the development of the arguments with underpin the TPNW, as well as in the diplomatic process that resulted in its negotiation and adoption (). The article synthesizes existing research and policy analysis and aims to draw out the implications for international nuclear weapons policy. It links the development of arguments critical of nuclear deterrence to the Humanitarian Impacts Initiative and to the subsequent legal and political framework of the TPNW. Much of the contemporary critique of nuclear deterrence has been sharpened within this framework, including through the consultative process on security concerns under the TPNW and the resulting report to the Third Meeting of States Parties (TPNW 2025 report). The author uses this article to advance these arguments as part of a wider policy debate rather than to present new data.
The article's central claim is that the accumulated evidence on nuclear consequences and risks produces a profound challenge to the normative and political legitimacy of nuclear deterrence as well as its security calculus. Nuclear deterrence doctrine rests on assumptions about rationality, credibility, crisis stability, control, limited escalation and the ability of political leaders to manage existential risk. Yet contemporary evidence suggests that the consequences of nuclear weapons use would be so widespread, transboundary and potentially irreversible that the reliance on nuclear deterrence imposes risks on populations, states and future generations that have no meaningful role in authorizing those risks. This creates a legitimacy problem for nuclear deterrence as a security policy, especially from the perspective of non-nuclear-weapon states whose populations would also be severely affected by nuclear weapon use yet they neither control nuclear arsenals nor shape the doctrines governing their potential use.
The article proceeds in seven sections. Section 2 revisits Hiroshima and Nagasaki through the lens of contemporary scientific knowledge. Section 3 explains the evidentiary asymmetry between well-documented nuclear consequences and the more speculative claims made on behalf of nuclear deterrence stability. Section 4 examines competing conceptions of security and normative implications of nuclear threats. Section 7 considers how nuclear deterrence narratives become entrenched in policy discourse and how humanitarian evidence can be integrated into multilateral diplomacy. Section 6 concludes by identifying policy implications for nuclear risk reduction, disarmament diplomacy and engagement across the NPT and TPNW communities.
2 Revisiting Hiroshima and Nagasaki: from memory to contemporary evidence
The atomic bombings of Hiroshima and Nagasaki have long served as the moral and historical reference point for nuclear weapons debates. Their destructive effects demonstrated a new category of violence: instantaneous mass killing, indiscriminate harm, radiation injury and long-term suffering across generations. For much of the nuclear age end especially after the Cold War, however, these events were often treated as historically exceptional rather than as indicators of a continuing and structurally embedded risk. Contemporary scientific research changes that framing. It shows that Hiroshima and Nagasaki were not only tragedies of 1945, but the first manifestations of a technological capacity whose humanitarian, environmental and societal consequences have become more complex as arsenals, delivery systems, urban vulnerability and global interdependence have evolved. Nuclear weapons are not merely instruments of localized devastation but catalysts of systemic global disruption and existential risk. Contemporary societies depend on tightly coupled supply chains, financial networks, energy grids, transportation systems, and digital infrastructures etc. The destruction of major urban and industrial centers would reverberate across borders through economic collapse, trade interruption, financial contagion, forced migration, and political and social destabilization. In an interconnected world, the consequences of nuclear use cannot be geographically contained ().
Research on the impacts of nuclear testing has also broadened the evidence base. The humanitarian consequences of testing in the Pacific, Kazakhstan, United States, Algeria, Australia, Polynesia and other regions demonstrate that nuclear harm is not limited to wartime use. Communities affected by testing have experienced displacement, contamination, cancer, intergenerational trauma, gendered and racialized impacts, inadequate compensation and long-term environmental degradation (; ; ; Alexis-Martin et al., 2021; ). These cases show that nuclear weapons policies have repeatedly externalized risk onto populations with limited political power. They also provide an important bridge between historical memory and present policy debate: nuclear risks are not hypothetical abstractions, but have already been borne unequally by affected communities.
The Humanitarian Impacts Initiative built on this evidence by shifting the diplomatic question from the strategic utility of nuclear weapons to the consequences of their use. The international conferences in Oslo, Nayarit and Vienna in 2013–14 created space for scientific experts, humanitarian organizations, survivors, affected communities and non-nuclear-weapon states to examine contemporary evidence about what happens when nuclear weapons are used—whether intentionally or through accident or miscalculation—and what are the risks of this happening (). The central proposition was simple but far-reaching: any credible assessment of nuclear weapons must begin with what these weapons do. This approach did not deny the existence of security concerns; rather, it challenged the narrowness of security discourse that treats nuclear deterrence benefits as central while relegating risks and consequences to the margins. Moreover, it facilitated the formulation of a different security perspective—of the non-nuclear majority of states—based on facts and up to date scientific evidence.
The evolution of this evidence base directly informed the TPNW. The treaty rests on the view that nuclear weapons are not only dangerous in the event of intentional use, but also unacceptable because of the risks embedded in their possession, deployment, modernization and doctrinal reliance—risks borne by all humanity and not merely the populations of nuclear armed states. This is why the TPNW's significance cannot be understood only as a legal prohibition. It is, thus, the codification of an alternative security paradigm grounded in humanitarian evidence, risk assessment and the perspectives of states and peoples exposed to nuclear dangers without controlling nuclear arsenals.
The critical implication of this scientific evolution is that nuclear weapons policy can no longer rely on simplified Cold War paradigms about nuclear deterrence and strategic stability that were developed in a bi-polar geopolitical context. The magnitude, complexity, and global scope of documented consequences require integrating humanitarian and environmental evidence into security assessments. The historical memory of Hiroshima and Nagasaki remains morally compelling, but contemporary science renders the stakes even clearer: nuclear weapons represent not only instruments of immediate destruction but also potential triggers of global systemic collapse.
3 The evidentiary asymmetry: consequences, risk, and nuclear deterrence assumptions
3.1 What the evidence shows
A central argument of this Perspective is that nuclear policy now operates within a striking evidentiary asymmetry. On one side stands a growing body of scientific and humanitarian research showing that nuclear use would produce catastrophic and potentially irreversible consequences. On the other side stand nuclear deterrence claims that depend heavily on assumptions about rational decision-making, stable communication, accurate perception, reliable command and control, and the controllability of escalation. The former is increasingly empirical and interdisciplinary; the latter remains largely inferential and counterfactual.
Studies of nuclear winter and climate disruption indicate that even a regional nuclear exchange could inject soot into the atmosphere, reduce sunlight, lower global temperatures and disrupt precipitation patterns. These effects would undermine food production far beyond the region of conflict (; , ; ; Xia et al., 2022). Related research on marine fisheries, agriculture and livestock production suggests that nuclear use could generate global food insecurity affecting billions of people. These findings expand the meaning of “nuclear consequences” beyond immediate casualties to include systemic disruption to climate, food systems, trade, development and political stability with global implications.
Other studies focus on health systems and humanitarian response capacity. They indicate that no national or international humanitarian response could adequately address the casualties, burns, radiation sickness, infrastructure destruction and psychological trauma resulting from even a single nuclear detonation in an urban area (; ; ). Hospitals would be destroyed or overwhelmed, medical personnel would be killed or injured, supply chains would fail and responders would face radiological hazards. The humanitarian system is therefore not merely underprepared; it is structurally incapable of responding adequately to nuclear weapons use.
Hence, the contemporary scientific record provides increasingly robust evidence that nuclear weapon use—whether large-scale or limited—would produce cascading, transboundary, and systemic effects. The humanitarian and environmental impacts are not confined to blast zones but extend through interconnected global systems. These risks are globalized and collective in nature. Nuclear weapons do not threaten only adversaries; they threaten planetary systems upon which all societies depend. In this sense, nuclear weapons represent a unique category of risk capable of undermining the ecological, economic, and social foundations of global civilization and future generations.
3.2 What nuclear deterrence assumes
By contrast, nuclear deterrence is often presented as a proven stabilizing force. Yet its claimed successes are not empirically verifiable in the same manner as the scientific findings regarding humanitarian and environmental consequences of nuclear weapons (; ). Nuclear deterrence theory rests on a series of interlocking assumptions. It presupposes rational actors capable of cost-benefit calculation under extreme stress; accurate perception and signaling; reliable command-and-control systems; absence of technical malfunction; and stable crisis management even amid escalating hostilities. It further presumes that all actors share common understandings of credibility and red lines. Contemporary work on psychology, organizational behavior, accidents and brinkmanship complicates these assumptions (; ). Historical near misses and command-and-control failures demonstrate that nuclear stability has depended not only on design but also on human judgment, institutional luck and the avoidance of technical or political failure.
Moreover, nuclear deterrence rests on the absence of nuclear war being interpreted as evidence that nuclear deterrence worked so far. Correlation is frequently treated as causation, despite the presence of multiple alternative explanatory variables, including political considerations, conventional military balances, economic reasons, normative taboos, and sheer contingency. Scholars have long warned against treating nuclear deterrence as certainty rather than as a contingent and historically fragile practice (; ; ; ).
The logic of nuclear deterrence is inherently future-oriented and speculative. It asserts that catastrophic consequences of its failure or accidents will not materialize because the threat of those consequences prevents adversaries from acting. Yet this assertion cannot be proven ex ante. It relies on a continuous chain of favorable contingencies that provide only a limited and highly speculative degree of certainty regarding its future effectiveness.
3.3 The burden of proof
The asymmetry between evidence and assumption has important policy implications. If the consequences of failure are global and irreversible, then the burden of proof should not rest on those questioning nuclear deterrence. It should rest on those who claim that nuclear deterrence can indefinitely manage these risks. This is one of the core arguments developed within the TPNW framework and in the report on security concerns under the treaty (TPNW 2025 report). The question is not whether nuclear deterrence has appeared to contribute to stability, but whether it can be regarded as legitimate when its failure would impose catastrophic harm on populations that have no agency in the decision to rely on it.
This point is particularly important because it shifts the debate away from a narrow question of doctrinal preference and toward a broader question of policy responsibility. If nuclear deterrence is defended as a public good—as a guarantee of security—then it must be evaluated in relation to the public harms that would follow from its failure. The humanitarian evidence base demonstrates that these harms would not be limited to belligerents or to the territories of nuclear-armed states but be far-reaching, global and potentially existential. In this sense, nuclear deterrence is not only a national security doctrine; it is a practice that distributes risk internationally while concentrating decision-making authority in the hands of a small number of states.
This risk-based framing does not require assuming that nuclear weapons use is inevitable. It requires recognizing that low-probability, high-consequence events demand a different standard of policy justification. Where the foreseeable effects include mass casualties, global food insecurity, environmental collapse and transboundary harm, the claim that nuclear deterrence is prudent must be assessed against the complexity and magnitude of the possible failure. The humanitarian evidence therefore shifts the debate from whether nuclear deterrence is strategically familiar to whether it remains ethically, legally and politically sustainable.
For non-nuclear-weapon states who are subject to the systemic risks generated by nuclear deterrence doctrines, the calculus appears particularly stark. From their perspective, rejecting nuclear weapons is not an abstract moral stance but a rational and realist response to collective vulnerability.
4 Security for whom? Competing perspectives and the TPNW
4.1 Divergent security narratives
The nuclear debate is increasingly marked by competing conceptions of security. Nuclear-armed states and their allies tend to define security in terms of nuclear deterrence, alliance assurance, strategic stability and the prevention of major war. Many non-nuclear-weapon states, by contrast, emphasize the insecurity created by nuclear weapons themselves: the risk of use, the humanitarian consequences of any detonation, the lack of response capacity, the environmental and economic spillovers and the unequal distribution of danger. These perspectives are not simply disagreements about policy instruments. They reflect different understandings of whose security counts and how risk should be assessed.
From the perspective of states relying on extended nuclear deterrence, nuclear weapons may appear as instruments of protection. From the perspective of states outside nuclear alliances, they appear as sources of imposed vulnerability. This is why the TPNW framework has placed such emphasis on security concerns of non-nuclear-weapon states. It challenges the idea that nuclear deterrence can be evaluated only from the standpoint of those who possess or benefit from nuclear weapons.
4.2 Agency, inequality and imposed risk
The distribution of nuclear risk is deeply unequal. Nuclear-armed states make decisions about doctrines, deployments, alert levels, modernization and threat signaling, while non-nuclear-weapon states and affected communities bear a significant share of the consequences. This creates a democratic and international legitimacy problem. Populations that would suffer from climate impacts, famine, radiation effects or economic and societal collapse do not participate in the policies that expose them to those risks. Nor do they have meaningful control over crisis behavior by nuclear-armed states.
This inequality is not accidental. It is built into the structure of the nuclear order. Nuclear-armed states define the conditions under which nuclear threats are considered necessary, while non-nuclear-weapon states are expected to accept the resulting risk as part of the international security environment. The humanitarian initiative contested this allocation of authority by insisting that states exposed to nuclear consequences have standing to assess the legitimacy of the policies that generate them. This is one reason the TPNW process was experienced by many participating states not only as a disarmament initiative but also as a reclamation of agency within nuclear weapons governance and discourse.
The Humanitarian Impacts Initiative and the TPNW responded to this problem by giving diplomatic agency to states and communities often marginalized in nuclear policy. The point was not merely to express moral concern, but to contest the structure of nuclear decision-making. By foregrounding humanitarian evidence, the TPNW recasts nuclear weapons as a collective security concern rather than as a matter solely for nuclear-armed states.
4.3 The TPNW as codification of an alternative paradigm
The TPNW codifies the conclusion that nuclear weapons are incompatible with humanitarian principles and with a sustainable understanding of security. It prohibits development, possession, transfer and use of nuclear weapons but also the threat of use. It thereby rejects the very foundation of nuclear deterrence, with the reasoning that the credible threat of inflicting catastrophic global consequences cannot be conceptually differentiated from the actual readiness—essential for the credibility of nuclear deterrence—of using nuclear weapons. The TPNW's broader significance therefore lies in the alternative paradigm it represents. It rejects the idea that security can legitimately be based on the credible threat of mass destruction. It also rejects the view that the humanitarian consequences and risks of nuclear use are secondary to strategic calculations or the security perspectives of some states.
The TPNW does not eliminate nuclear weapons by itself or resolves all questions of verification, sequencing or geopolitical conflict. Rather, it establishes a normative, legal and political framework through which nuclear weapons can be assessed from the standpoint of humanitarian consequences, risk and legitimacy. For this reason, criticism that the TPNW does not immediately produce disarmament misses part of its function und misunderstands its theory of change. Its purpose is legal and normative but also to change the terms of debate, strengthen stigma, articulate the security concerns of non-nuclear-weapon states and, hence, to provide a policy platform for challenging security paradigms based on nuclear deterrence reliance, the threat of global mass destruction and the nuclear status quo.
The TPNW's contribution is to insist that humanitarian consequences, environmental risks, intergenerational harm and unequal vulnerability are not peripheral. They are central to assessing nuclear weapons. This does not end the strategic debate, but it changes its burden. Defenders of nuclear deterrence must respond not only to abstract arguments about stability but to evidence about what nuclear use would do and to the security concerns of states that reject being placed under nuclear risk ().
Progress on nuclear disarmament will require engaging on these divergent security perspectives meaningfully rather than dismissing them. The tension between these paradigms is not peripheral to nuclear diplomacy—it is its central fault line. Understanding and addressing it is essential to any credible reassessment of nuclear weapons as “weapons of peace” or as instruments whose continued legitimacy is increasingly untenable (TPNW 2025 report).
5 Reframing nuclear deterrence discourse and multilateral diplomacy
5.1 The normalization of nuclear deterrence
Nuclear deterrence has become deeply normalized in the policy language of nuclear-armed states and alliances. It is often described as responsible, necessary and stabilizing, while alternatives are portrayed as unrealistic or naive. This discursive structure matters because it shapes what is considered legitimate expertise. Humanitarian evidence is sometimes treated as morally important but strategically secondary. Risk-based critiques are acknowledged but rarely allowed to alter doctrine. As a result, nuclear deterrence discourse can become self-reinforcing.
This normalization has important consequences. By repeatedly equating nuclear weapons as a “security guarantee,” states reinforce the perception that such weapons confer status, protection, and strategic indispensability (). This, in turn, incentivizes proliferation and undermines the normative stigma that has historically constrained nuclear use. This normalization also affects institutional practice. Nuclear policy communities often reward technical expertise on force posture, escalation management and alliance reassurance, while treating humanitarian evidence as external to the core security debate. The result is an epistemic imbalance: the knowledge needed to maintain nuclear deterrence receives sustained institutional attention, whereas the knowledge needed to assess the human, ecological and systemic consequences of nuclear deterrence failure is often compartmentalized.
Policies that are grounded in the humanitarian initiative challenge this normalization and seek to correct that imbalance by insisting that consequences are not peripheral to security; they are a central measure of whether a policy is responsible. The question is not whether states currently rely on nuclear deterrence; clearly they do. The question is whether policy discourse has adequately interrogated the assumptions, risks and externalities of that reliance. The Humanitarian Impacts Initiative and the TPNW have opened space for such interrogation by placing consequences at the center of security analysis.
5.2 Integrating humanitarian evidence into security debate
Integrating humanitarian evidence into security debate does not mean replacing strategic analysis with moral assertion. It means recognizing that any responsible strategy must account for consequences, uncertainty, accident risk, escalation dynamics and the distribution of harm. Moreover, little to no information exists to what extent this evidence forms part of strategic analysis and nuclear planning in nuclear armed states, in particular as it pertains to the impact of nuclear weapons in third countries and globally. Nuclear deterrence debates should therefore include scientific evidence on climate effects, food systems, health care collapse, gendered and intergenerational impacts, and the inability of humanitarian systems to respond. These findings should inform alliance policy, nuclear posture reviews, crisis-management planning and risk-reduction discussions and form a central part of the global nuclear discourse.
The report on security concerns under the TPNW is important in this respect because it translates humanitarian evidence into security language (TPNW 2025 report). It argues that nuclear weapons themselves generate security concerns for non-nuclear states, including risks of use, accident, miscalculation, coercion and environmental harm. This framing challenges the idea that only nuclear-armed states have security concerns relevant to nuclear policy and provides a basis for dialogue across treaty communities. Rebalancing this discourse requires broadening the analytical framework to include the full range of consequences and affected actors. A serious and credible international security policy and nuclear weapons discourse must confront the totality of risks—including those borne by states not party to nuclear deterrence arrangements.
5.3 Multilateral diplomacy and bridge-building
The current nuclear order is highly polarized. Nuclear-armed states and many allies criticize the TPNW for not reflecting the security environment, while non-nuclear states criticize nuclear-armed states for perpetuating a dangerous and unequal system. This divide is real. However, dismissing or refusing to engage with the profound underlying arguments on the humanitarian consequences and risks of nuclear weapons on which the TPNW is based risks deepening divides. The treaty is rooted in humanitarian evidence and legal reasoning that deserve substantive engagement. Even states that do not join the TPNW, indeed the entire international security policy discourse, would benefit from addressing its core critique: the urgent need of weighing today's scientific evidence on catastrophic humanitarian harm and risk of nuclear weapons with claims of security legitimacy of nuclear deterrence.
Constructive interaction between NPT and TPNW processes could help bridge discursive divides. Both frameworks ultimately seek to prevent nuclear war. Both operate within the broader architecture of international law. Enhanced dialogue that seriously engages with scientific evidence (), humanitarian consequences, and legitimacy concerns could gradually narrow the gap between nuclear deterrence-centered and humanitarian consequences and risk-elimination perspectives (TPNW 2025 report).
A policy-oriented Perspective should therefore identify practical entry points. One is to strengthen the role of humanitarian evidence in NPT discussions. Another is to encourage nuclear-armed states and allies to engage seriously with the security concerns articulated by TPNW states parties, even if they do not join the treaty. A third is to develop joint work on nuclear risk and humanitarian and environmental consequences. Such engagement would not resolve disagreements over nuclear deterrence, but it would reduce the tendency to speak past one another.
Policy engagement should occur around shared factual premises: nuclear use would be catastrophic; risks of accident and miscalculation exist; humanitarian response capacity would be inadequate; and the prevention of nuclear war is a common interest of the highest order.
6 Conclusion: reassessing legitimacy and rebalancing nuclear security discourse
Eighty years after Hiroshima and Nagasaki, the central question confronting the international community is not only how to remember the past, but how to evaluate the present legitimacy of nuclear weapons policy. The historical narrative of the atomic bombings has long served as a moral reference point. This article has argued that nuclear deterrence must be reassessed in light of the expanding evidence base on humanitarian consequences and nuclear risks. Its purpose has been to promote a policy perspective developed through the Humanitarian Impacts Initiative and the TPNW framework. The policy intervention is that nuclear deterrence debates should no longer proceed as if the consequences of nuclear use are secondary to strategic doctrine. They are central to any assessment of legitimacy.
Three policy implications follow. First, nuclear risk reduction must be broadened. It should encompass a serious engagement with the humanitarian, environmental and systemic consequences of nuclear use. In short, it should focus on what happens if nuclear deterrence fails rather than trying to manage the risks of nuclear deterrence. Second, disarmament diplomacy should integrate the security concerns of non-nuclear-weapon states. These concerns are not rhetorical additions to the debate; they are grounded in evidence about transboundary and global harm. Third, nuclear-armed states and allies should address the burden of proof problem. If they claim that nuclear deterrence is necessary and stable, they should explain how this claim can be reconciled with the catastrophic consequences of nuclear deterrence failure and with the risks of accident, miscalculation and escalation.
A fourth implication concerns language. Nuclear policy debates should avoid treating nuclear deterrence as synonymous with security. Nuclear deterrence is one historically specific policy practice, not security itself. Once this distinction is made, alternative security approaches become easier to discuss: reducing nuclear salience, delegitimizing threats of use, strengthening negative security assurances, lowering operational risks, addressing the legacy of nuclear harm and pursuing legal measures toward elimination. The TPNW contributes to this broader vocabulary by articulating security as protection from nuclear weapons rather than protection through nuclear weapons.
The TPNW has changed the nuclear debate. It has codified a humanitarian and risk-based critique of nuclear weapons and has provided a forum for developing arguments that challenge arguments about the sustainability and legitimacy of nuclear deterrence. The report on security concerns under the TPNW represents an important step in this evolution because it translates humanitarian evidence into a cogent and legitimate security perspective of non-nuclear states. It shows that the states rejecting nuclear weapons are not ignoring security; they are advancing a different conception of it.
For future diplomacy, the question is therefore not whether humanitarian evidence and nuclear deterrence arguments can be forced into consensus. They cannot be reconciled easily, because they begin from different assumptions about risk, responsibility and legitimacy. At the least, however, nuclear-armed states should be expected to justify that reliance in light of the increasing body of scientific evidence about the known consequences of nuclear use and the security concerns of other states. This expectation itself would represent a meaningful change in nuclear discourse.
The empirical evidence on nuclear consequences demands a more rigorous policy debate about risk, legitimacy and responsibility. If nuclear weapons are capable of producing global catastrophe, then all states have a legitimate interest in the doctrines and policies that create that risk. The task ahead is not only to reduce the probability of nuclear use, but to reassess the political and normative foundations of a security system that continues to depend on the threat of unacceptable harm.
If the international community is willing to reassess entrenched assumptions and to confront the implications of its own scientific knowledge, a transformation of nuclear weapons and security discourse is possible. In that transformation lies the most meaningful way to honor the legacy of Hiroshima and Nagasaki: not only by remembering their devastation, but by ensuring that the policies governing nuclear weapons are subjected to the highest standards of evidence, legitimacy, and justice. Given the current trends of increased reliance on nuclear weapons, the urgency of such a transformation cannot be overstated.
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AK: Writing – original draft.
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Summary
Keywords
nuclear weapons, humanitarian consequences, international law, international security, legitimacy, nuclear deterrence, nuclear disarmament, nuclear risk
Citation
Kmentt A (2026) Weapons of peace or instruments of catastrophe? Rethinking nuclear deterrence, legitimacy, and security in light of humanitarian evidence. Front. Polit. Sci. 8:1835970. doi: 10.3389/fpos.2026.1835970
Received
21 March 2026
Revised
13 May 2026
Accepted
21 May 2026
Published
19 June 2026
Volume
8 - 2026
Edited by
Tatsujiro Suzuki, Peace Depot, Japan
Reviewed by
Yujin Julia Jung, Mount St. Mary's University, United States
Laura Considine, University of Leeds, United Kingdom
Updates
Copyright
© 2026 Kmentt.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Alexander Kmentt, alexander@kmentt.eu
Disclaimer
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