The nuclear relationship between China and the United States and its allies is increasingly shaped by widening perception gaps rather than deliberate strategic design. While both sides share a fundamental interest in avoiding nuclear conflict, they diverge on core questions, including the role of nuclear weapons, the likelihood of first use, the conditions for credible deterrence, and the requirements for effective reassurance. These differences, reinforced by internal ambiguities and evolving military capabilities, risk driving costly and potentially open-ended competition that neither side fully intends but both may find difficult to contain. In some cases, these dynamics reflect a classic security dilemma: Measures taken by one side to strengthen its own security generate action-reaction cycles that heighten insecurity on the other. Yet existing scholarship doesn’t often probe the deeper sources of the perception gaps that drive these dynamics in the first place.

This paper examines these dynamics across six issue areas, each combining analytical assessment with policy recommendations. It analyzes how questionable assumptions and doctrinal ambiguity drive divergence over the scope of nuclear deterrence objectives, the credibility of no-first-use (NFU) commitments, approaches to escalation management, and the implementation of high-level principles. It also examines how these dynamics play out in differing conceptions of strategic stability, disputes over missile defense, emerging challenges in outer space, and rising risks of regional proliferation interact to reinforce mutual suspicion and action-reaction dynamics. Across these domains, the paper identifies both sources of divergence and practical opportunities for convergence, including targeted measures on transparency, signaling, restraint, and the management of disagreement.

The purpose of this analysis is not to assign blame, but to heighten sensitivity to the dynamics of the security dilemma and encourage salutary reflection in policy deliberation by illuminating how the two sides interpret the same behaviors in divergent ways. The paper shows how one party’s policies may appear threatening or destabilizing to the other, often without the former’s awareness. It therefore underscores the need for both Beijing and Washington to assess the costs and consequences of their own policy choices more rigorously, rather than defaulting to worst-case interpretations of adversary intent.

Ultimately, mitigating the risks of arms racing and nuclear conflict will depend less on immediate arms control agreements, for which there is little foreseeable prospect, than on whether both sides are willing to align their policies with their stated objective of preventing nuclear war. By clarifying strategic priorities, constraining unnecessary competition, and engaging more seriously with the sources of mutual mistrust, China and the United States and its allies can move toward a more stable and constructive nuclear relationship. Table 1 distills the main issue areas where productive engagement could advance that objective and summarizes the key policy recommendations developed in the six sections that follow.

China and the United States disagree which side’s strategy is more aggressive, and this poses a fundamental challenge in their nuclear relationship. Each tends to view and characterize the strategy of its adversary as dangerous, while seeing its own actions as simply responsive to the evolving threat.

Mainstream Chinese analysis assesses nuclear aggressiveness through two questions: whether a state seeks to use nuclear weapons to address non-nuclear threats, rather than solely to deter and counter nuclear ones; and whether it aims to achieve military victory through nuclear warfighting. China traditionally characterizes its own nuclear strategy as limited to deterring nuclear threats, and Beijing rejects the objective of winning a nuclear war.¹ In contrast, it views U.S. strategy as embracing a more expansive role for nuclear weapons that includes addressing non-nuclear threats, which has been articulated in successive U.S. Nuclear Posture Reviews and related national security documents. Scholarly debates in the United States over nuclear primacy, defined as the capability to disarm an adversary’s nuclear forces, have reinforced Beijing’s concerns. So has official U.S. emphasis on damage limitation, understood as reducing harm by limiting an adversary’s retaliatory strike. Together, these debates and policies have strengthened Beijing’s conclusion that Washington maintains a warfighting-oriented nuclear posture.

The United States, for its part, acknowledges retaining the option of nuclear first use, though only under extreme circumstances threatening the vital interests of the United States or its allies. Its primary objective, particularly with respect to China, remains deterring Chinese first use—which it sees as an increasingly salient concern in light of Beijing’s ongoing and unexplained nuclear arsenal expansion. At the same time, Washington rejects the characterization that it pursues nuclear warfighting. It frames damage limitation as a rational objective enabled by superior military capabilities. Yet, as they assess China’s nuclear policies, American strategists tend to believe that like any nuclear power, China would employ nuclear coercion to maximize security gains. Thus, they expect Beijing to threaten nuclear escalation in the face of conventional defeat in order to compel U.S. de-escalation and secure conflict termination on terms favorable to China—a more aggressive strategy than is implied by Chinese statements. To the extent China has not openly embraced a more expansive nuclear objective, American strategists tend to believe it has more to do with capability constraints than political restraints.

This perception gap is exacerbated by mistrust, misinterpretation, and lack of clear information, but ultimately rooted in ambiguities within both countries’ internal nuclear thinking. Clarifying strategic objectives ultimately boils down to reducing unintended ambiguity in one’s conceptions of deterrence objectives, including on the increasingly salient issue of escalation management.

These internal uncertainties have only deepened in recent years. Beijing has not officially explained the purpose and end point of its nuclear buildup. Thus, Washington has sought to recalibrate its traditional policies amid significant uncertainty about the implications of China’s evolving posture. For China, the buildup appears to be driven primarily by a political mandate to build a world-class military and to demonstrate capabilities expected to shape the strategic environment vis-à-vis the United States in China’s favor.² Initially, this expansion appears to have outpaced the development of a coherent military strategy, but that gap is likely to narrow as PLA strategists consolidate internal thinking and articulate updated military rationales and objectives. This evolving dynamic, further shaped by changing U.S. threat perceptions and responses, as well as Chinese interpretations of them, amplifies both the complexity and the consequences of strategic ambiguity.

The Limits of Nuclear Deterrence Objectives?

While often underappreciated, there appears to be some shared belief among American and Chinese nuclear experts about the limited utility of nuclear first use. For instance, most U.S. experts do not consider nuclear first use against China necessary or even useful except in the most extreme scenarios. Similarly, Chinese strategists have perceived little military need for nuclear first use, while their confidence in China’s conventional capabilities has continued to grow. Despite China’s recent nuclear buildup, Chinese strategists still view the United States as holding significant and enduring nuclear advantages, further reducing Beijing’s incentive to deliberately escalate a conventional conflict with Washington into the nuclear domain.

While often underappreciated, there appears to be some shared belief among American and Chinese nuclear experts about the limited utility of nuclear first use.

However, poor understanding of each other’s strategic objectives is fueled by several ambiguities in each country’s nuclear logics. Some of these ambiguities are purposeful, while others reflect debate and a lack of settled thinking. In both cases, these ambiguities likely drive each party to see the other as more likely to escalate a conflict to nuclear use than their planning actually indicates.

Shifts in the military balance over the past decade have led more American strategists to view deliberate ambiguity over U.S. nuclear first use as strengthening deterrence against Chinese conventional aggression. As Washington has come to recognize the rapid growth of China’s conventional military capabilities, more analysts have examined the possibility that the United States could decide to threaten nuclear escalation if it is losing a conventional war.³ This expanding expert debate over compensating for declining conventional advantages makes it easy for China to infer a stronger U.S. propensity to escalate from conventional to nuclear conflict than U.S. planners may intend.

For the foreseeable future, the U.S. homeland faces no existential threat from conventional attack. Therefore, the most plausible scenario in which Washington could employ nuclear weapons first is for the defense of U.S. allies in regions where the United States may lack conventional superiority. Indeed, a leading argument for retaining the option of using nuclear weapons first has been the need to reassure U.S. allies under the extended nuclear deterrence umbrella of Washington’s willingness to use nuclear weapons for their defense. This rationale, however, is eroding in light of shifting political dynamics in Washington. The second Donald Trump administration has pushed U.S. foreign policy debates in a markedly “America First” direction, making it increasingly difficult to envision Washington running the existential risk of initiating nuclear war against another nuclear power on behalf of an ally. That threshold has always been extraordinarily high. Even when the United States was far more willing to expend blood and treasure in defense of its allies, the credibility of its willingness to employ nuclear first use against another nuclear power on their behalf was often questioned. Even after Trump leaves office in 2029, the domestic appeal of “America First” is likely to have a lingering effect, making it prudent for U.S. military planners to invest more heavily in options that do not depend on a future president’s willingness to authorize nuclear first use in defense of an ally. By contrast, the credibility of threatening nuclear retaliation in response to an adversary’s nuclear first use against an ally rests on a stronger and more durable political foundation for extended deterrence.

If nuclear first use on behalf of an ally has become increasingly untenable, then some of the deliberate ambiguity in U.S. nuclear strategy can be reduced.⁴ As U.S. political will grows increasingly uncertain, it may become more compelling for the United States to prioritize conventional deterrence and warfighting capabilities while narrowing the role of nuclear weapons to deterring and responding exclusively to nuclear threats. Ultimately, employing conventional capabilities to defend allies places the lowest demands on political will and is therefore the most credible option, although sustaining a conventional deterrence-by-denial posture is highly resource-intensive. A shift away from nuclear first use toward a more focused and credible nuclear strategy would therefore also ease resource allocation tradeoffs between nuclear and conventional missions, and even help mitigate inflated external nuclear threat perceptions, including in China.

For its part, China’s growing confidence in its conventional military advantages over the United States in East Asia has reinforced its traditional theory of victory: prevailing through conventional means, with nuclear forces focused on deterring U.S. nuclear escalation. For at least the past decade, China has interpreted U.S. investment in tactical nuclear capabilities as evidence of greater reliance on nuclear first use to compensate for declining U.S. conventional advantages.

That said, within certain quarters of the PLA, there is some apparent reluctance to unequivocally limit China’s own nuclear objectives to deterring nuclear first use. Some PLA experts, including National Defense University professor Li Xianrong, argue that China’s long-standing no-first-use policy is grounded partly in its historically inferior nuclear capabilities relative to the United States, which would make initiating nuclear escalation militarily irrational. However, linking the scope of China’s nuclear objectives to relative capability—as opposed to doctrine, morality, legality, or other policy foundations—leaves open the possibility of policy adjustment as China’s capability evolves. More importantly, Li suggests that strategic ambiguity itself may serve China’s interests: If U.S. decisionmakers have doubts about the credibility of China’s limited nuclear objectives, that uncertainty could inject caution into U.S. decisionmaking.⁵

Consistent with this view, the most recent PLA doctrinal materials that were leaked into the open-source domain,⁶ along with earlier writings by former Second Artillery deputy commander Zhao Xijun,⁷ indicate that China’s missile forces have developed options for nuclear signaling to deter non-nuclear strategic attacks. These sources emphasize that the authority to actually carry out nuclear strikes rests exclusively with political leadership, placing it beyond the military’s remit to speculate. Yet, they suggest that the more credible China’s nuclear threats in a conventional conflict, the less likely actual use becomes. This logic implicitly establishes a conditional first use option, limited to extreme scenarios and contingent on explicit political authorization. In turn, this contributes to U.S. skepticism regarding the limited scope of China’s stated nuclear objectives.

Nuclear Escalation Management

Preparing for deterrence failure, regardless which party uses nuclear weapons first, necessitates engaging the difficult topic of managing escalation once the nuclear threshold is crossed. On this issue, U.S. and Chinese approaches have long diverged, although some convergence now appears to be emerging. That convergence in perceived benefits, however, does not necessarily extend to shared understandings of the risks of nuclear conflict spiraling out of control or of the potential for renewed arms race dynamics.

U.S. strategists and nuclear planners have long embraced the desirability of escalation management capabilities designed to enable calibrated responses at successive rungs of the escalation ladder. These include capabilities that not only support proportional responses, but also demonstrate advantage and, if necessary, prevail at any level of escalation. In the extreme, if escalation appears likely to spiral out of control, Washington would seek to destroy a sufficiently large portion of the adversary’s remaining nuclear forces to limit further damage. The pursuit of escalation dominance in this manner, however, is inherently competitive and often zero-sum.

Exactly when escalation becomes unmanageable and damage limitation comes into play, and how the capability requirements for escalation management and escalation advantage converge or diverge, remains unclear in U.S. thinking, at least in publicly available literature. U.S. planners may wish to avoid articulating a clear standard publicly for various reasons, including its perceived deterrent value, uncertainty about presidential decisionmaking, or the lack a fully developed internal definition. Regardless, the absence of a clear delineation of the capability requirements for prudent escalation management and “meaningful” damage limitation, as well as how the latter differs from disarming first strike capabilities, reinforces China’s worst-case interpretations of U.S. intent.  

For China, growing confidence in the survivability of its intercontinental second-strike capability against the United States may naturally elevate the importance of addressing escalation management. The PLA has long recognized the limitations of its traditional massive retaliation strategy and has invested in more flexible theater-range nuclear forces capable of limited responses. The key question is how far this effort should extend, both at and beyond the theater level.

China need not fully embark on the path of managing nuclear escalation in the manner pursued by the United States, with aspirations of escalation dominance or even, ultimately, damage limitation. Earlier generations of Chinese leaders deliberately avoided this path, partly due to weaker capabilities and partly due to skepticism that nuclear escalation can be controlled, let alone managed. Instead, they focused on deterring nuclear war altogether. That restraint now appears to be eroding, driven by capability growth, U.S. persistence in pursuing escalation management, and directives from Chinese President Xi Jinping emphasizing war control and containment.⁸ This shift has been accompanied by increased PLA writings on managing the “process of military struggle.”⁹

Exposure to U.S. debates has likely reinforced the view among PLA strategists that escalation management capabilities can strengthen deterrence, including by discouraging lower-level provocations. The main constraints are cost-benefit calculations and political approval. The latter may not be decisive, given Xi’s apparent willingness to support initiatives that enhance perceived strategic deterrence against the United States. The aim to reduce long-standing asymmetries in the bilateral deterrence relationship may further strengthen the case for investing in escalation management.

The primary constraint, therefore, is cost. Advanced escalation management capabilities are potentially open-ended and expensive. From a military perspective, the ability to respond proportionally at each escalation level is preferable to lacking such capability, but still inferior to achieving escalation dominance across levels, potentially extending to large-scale damage limitation. At the high end, China faces no clear technological barrier to building a force comparable to, or even exceeding, that of the United States if it chooses. Because sufficiency is defined relative to the adversary, competition in escalation management risks becoming effectively unbounded. Sustaining a significantly larger and more diverse nuclear arsenal would entail substantial long-term operational and maintenance costs, however, which must be incorporated into force planning.

Against these costs, the marginal deterrence benefits appear limited, however. Even during periods of heightened Chinese concern about U.S. strategic hostility in the late 2010s, there was no strong belief within China’s policy community that the United States sought to initiate nuclear war.¹⁰ While some U.S. experts have discussed greater reliance on nuclear weapons amid diminishing conventional military advantages, a declining political willingness in Washington to fight major wars on behalf of allies suggests a reduced need for China to expand nuclear capabilities far beyond its traditional focus on deterring nuclear first use. Investing heavily in escalation management to prepare for the aftermath of U.S. nuclear first use, an already extreme scenario that is becoming less plausible, risks diverting attention from more realistic security threats.

Opportunities for Convergence and Restraint

Further downplaying, if not fully ruling out, deliberate nuclear escalation in a conventional war serves both countries’ security interests, albeit for the somewhat different reasons discussed above. In particular, given the lack of Chinese incentive to resort to nuclear first use and the reality of diminishing American political appetite for assuming existential risks on behalf of distant allies, an explicit renunciation of both sides’ first use options has become increasingly aligned with American interests. Rather than weakening its deterrence, such a policy could strengthen U.S. credibility, especially if it allows Washington to address the more critical deterrence gap emerging at the conventional military level. Although debates over the “sole purpose” of nuclear weapons have long been framed as questions of declaratory policy,¹¹ recent shifts in the security and geopolitical environment warrant reconsidering the issue not merely at the declaratory level but as part of a broader reassessment of the nuclear planning assumptions that underpin U.S. strategy.

Defining the purpose of nuclear strategy around deterring an adversary’s first use would also bring greater clarity to strategic planning. Admittedly, demonstrating a capability for escalation management, or even escalation dominance, following the outbreak of nuclear war could further strengthen deterrence against first use. Yet any marginal gains in deterrence should be weighed against the additional investments required, their associated opportunity costs, and the risk of fueling competition in escalation management. In practice, decisions about the extent to which states should prepare to respond to nuclear first use in the event of deterrence failure should be guided by nuanced assessments of the adversary’s incentives for nuclear first use, or the lack thereof, rather than purely by worst-case speculation or mirror-imaging. Such decisions should also be informed by efforts to secure credible reassurance regarding the adversary’s commitment to refrain from nuclear first use.

Admittedly, reducing reliance on, or even abandoning, the option of nuclear first use could modestly weaken deterrence against an adversary’s conventional aggression. However, investing in robust conventional deterrence-by-denial capabilities offers a more credible and ultimately more effective means of deterring such aggression.

If Washington and Beijing each correctly conclude that preventing nuclear war, rather than preserving the option to initiate it, best serves their interests, they would benefit from clearly signaling this to each other.

If Washington and Beijing each correctly conclude that preventing nuclear war, rather than preserving the option to initiate it, best serves their interests, they would benefit from clearly signaling this to each other and to the broader international community. Clarifying positions against nuclear first use, the absence of which has fueled mutual threat perceptions, could enable a joint or reciprocal political statement affirming a shared interest in preventing nuclear conflict, or more specifically, preventing nuclear first use by any country. Such a step would also signal a willingness to break from the historical pattern of fluctuating reliance on nuclear weapons based on shifts in conventional military power, a pattern that has long impeded efforts to reduce the salience of nuclear weapons in national security strategy.

Some American strategists may perceive strategic value in sustaining Chinese uncertainty about potential U.S. first use. Such uncertainty could induce Beijing to allocate greater resources to nuclear forces, thereby limiting its ability to compete for conventional military advantages. Nonetheless, even assuming Washington is not genuinely concerned about China’s nuclear expansion, which itself appears doubtful, it remains far from clear that deliberately encouraging nuclear competition with Beijing would advance U.S. interests. For the foreseeable future, the United States appears more constrained than China in revitalizing its nuclear production base, whereas China has demonstrated the capacity to rapidly expand its nuclear production infrastructure and may be better positioned to scale its nuclear forces at lower marginal cost if required.

American strategists may also worry that shifting resources away from managing nuclear escalation and toward strengthening conventional capabilities could create incentives for Chinese nuclear first use as Beijing’s conventional advantages narrow. Yet if Washington succeeds in reversing the unfavorable trend in the conventional military balance and places escalation pressure back on Beijing, that is a considerably more manageable problem than the current trajectory of declining U.S. conventional deterrence credibility. For Beijing, growing confidence in matching and potentially surpassing U.S. conventional capabilities would likewise make a greater emphasis on conventional competition an acceptable proposition. Even in the unlikely event, as Beijing would assess it, of a successful U.S. effort to again tilt conventional competition in Washington's favor, Beijing would pay enormous costs by resorting to a nuclear first use strategy, given the extent to which the credibility and international reputation of China’s nuclear posture have long been anchored in its categorical renunciation of first use.

Building on a shared commitment to prioritizing the prevention of nuclear conflict, both sides should engage in substantive dialogue on whether and how such a commitment can be made credible. This requires a willingness to examine evidence and engage substantively with operational-level issues, rather than restating fixed high-level positions. Even the act of engaging in good-faith exchanges would send a constructive signal. As discussed later, these issues are operationally complex and resist simple solutions. The difficulty is especially acute if credibility is defined in terms of force structure. Such credibility is inherently hard to evaluate because of government secrecy and security considerations that extend beyond the bilateral relationship.

The perceived need for nuclear escalation management affects whether both sides can credibly reassure one another that preventing any nuclear first use remains a priority. Although fully credible commitments to renounce first use may remain difficult to establish, reassurance efforts can still shape assessments of how much escalation management capability is necessary.

Both countries need clearer internal thinking on how much escalation management capability is genuinely necessary. Given the extremity of nuclear use scenarios and the need to balance marginal deterrence gains against opportunity costs and arms race risks, a strong case could be made for a limited capability to respond in kind at major escalation rungs. As long as China can hold different types of targets at risk across tactical, regional, and intercontinental ranges, such a limited in-kind response posture would give national leaders meaningful flexibility in rare cases of deterrence failure while relying on assured second-strike capability as the ultimate deterrent against all-out nuclear war.

Beyond this threshold, more expansive capabilities would be harder to justify. These include large-scale proportional responses at every rung, pursuit of escalation dominance, or development of damage-limitation capabilities. Such options would likely yield uncertain, though probably rapidly diminishing, deterrence benefits while imposing substantially higher costs and increasing the risks of action-reaction dynamics. The resource demands would likely become prohibitive, especially as adversaries respond with their own arsenal expansions. Unless the goal is to impose costs on an adversary through a deliberate or deceptive arms race, a strategy that carries substantial downsides as discussed above, both the United States and China would benefit from clear internal decisions to avoid pursuing such extensive escalation management capabilities.

China should undertake a comprehensive internal review of escalation management, drawing on expertise from both civilian and military research communities. A broader analysis could help mitigate narrower views held by highly cleared PLA experts that tend to favor more expansive capabilities by incorporating a wider range of perspectives without necessarily compromising sensitive information. If such a review supports limiting escalation management capabilities, China should articulate this position publicly and reinforce it in official dialogues with the United States. A restrained approach focused on limited objectives would be more credible and understandable to external observers, including U.S. strategists, than an ambiguous and open-ended posture that fuels internal incoherence and external suspicion of more ambitious objectives. Heightened U.S. suspicion, in turn, increases the risk that Washington dismisses the likelihood of a deterrence spiral and accelerates its own nuclear buildup.

On the U.S. side, nuclear force planning should be grounded in a nuanced understanding of Chinese nuclear thinking. Chinese military strategists continue to perceive clear U.S. nuclear advantages across both tactical and strategic domains. There is little publicly available evidence that China perceives a U.S. nuclear deterrence gap and seeks to exploit it. At the same time, long-standing U.S. fascination with damage limitation is likely to prove prohibitively costly and operationally challenging against a peer competitor whose economic capacity and industrial advantages significantly exceed those of the Soviet Union at its peak during the Cold War arms race. China’s adoption of more responsive postures, including launch-under-attack, further complicates the feasibility and reliability of damage limitation.

Given the limited deterrence returns from further investment in capabilities in which the United States already enjoys clear advantages, and their limited relevance in plausible conflict scenarios, Washington should avoid becoming locked into pursuing damage limitation. Instead, it should prioritize more credible, usable, and operationally consequential capabilities, particularly in conventional deterrence, where the production and scaling gap with China is both more pronounced and potentially widening. Clarifying this priority internally, including by de-emphasizing nuclear escalation dominance, would strengthen overall deterrence. It would also reduce incentives for Beijing to pursue extensive counterforce capabilities of its own, thereby discouraging further nuclear expansion.

As international attention to China’s nuclear buildup has increased, Beijing has intensified its advocacy of no-first-use, including by formally proposing the core elements of a potential NFU treaty.¹² As China advances NFU as its primary counterproposal to U.S. and broader international efforts to promote nuclear arms control talks, it is difficult to initiate serious dialogue without engaging this issue directly. Chinese NFU ideas offer a potentially rich area for constructive discussion, provided both sides identify the right questions.

A useful first step is for Beijing and Washington to recognize and address the practical difficulty of reaching shared judgments about China’s incentives for nuclear first use. A central obstacle here lies in their differing evaluations of relative conventional military strength. China’s confidence that it can secure core security interests, including a potential military takeover of Taiwan, through conventional means, without resorting to nuclear first use, is not widely shared in Washington. Many American strategists instead view a failed Chinese invasion of Taiwan as a plausible scenario that could place extraordinary pressure on Beijing to consider nuclear threats or even nuclear use.

These divergent assessments are rooted in factors that are difficult to reconcile. These include differing historical experiences with large-scale amphibious operations and the absence of real-world testing of the PLA’s modern capabilities, including weapons systems, training, and operational doctrine, against Taiwanese or U.S. forces.

Given this persistent divergence in views about operational incentives, the key question becomes whether China’s, or any country’s, political decision to fully rule out nuclear first use can be made credible to the other side. This remains a central point of disagreement between Washington and Beijing, one that has not yet been sufficiently clarified through sustained dialogue.

Sources of Distrust

In general, the credibility of a country’s NFU commitment faces several challenges, some of which are especially salient in light of China’s characterization of its nuclear posture to date.

First, ambiguity over what constitutes nuclear first use complicates assessments of compliance. In the midst of an intense conventional conflict, a state facing military setbacks may seek to exploit nuclear coercion by signaling readiness to escalate while preserving ambiguity to maintain flexibility and deniability, thereby limiting the risk of adversary overreaction. Actions such as a nuclear demonstration shot over open ocean, or, more dramatically, a high-altitude nuclear detonation framed as a test that disables adversary satellites without causing casualties, could generate disagreement over whether nuclear first use has in fact occurred.

Second, the way the PLA interprets China’s NFU policy introduces additional uncertainty. NFU is understood to prohibit the actual first use of nuclear weapons but not necessarily the threat of such use, so long as the threat is not carried out.¹³ A nuclear threat, moreover, need not take the form of an explicit declaration of intent. In practice, overt statements are often unnecessary; a range of signaling activities,¹⁴ including nuclear exercises or the mobilization of nuclear forces, can be sufficient to generate a perception of threat in the target state.

This implicit allowance for nuclear first use threats is particularly striking when compared with China’s declaratory policies on related issues. China’s negative security assurance to non-nuclear weapon states prohibits both use and threat of use of nuclear weapons;¹⁵ its position on chemical weapons similarly rejects both use and threat of use;¹⁶ and its joint proposal with Russia on preventing the weaponization of outer space includes prohibitions on both use and threat of force against space objects.¹⁷

Leaving open the option of threatening nuclear first use carries two major drawbacks. It enables nuclear coercion, which relies primarily on credible threats, and it undermines the core purpose of NFU by eroding confidence in the commitment itself. An adversary cannot reliably distinguish between bluff and genuine threats and therefore will assume the worst. Indeed, the PLA’s missile force has developed concepts for making nuclear threats appear credible when deemed necessary to deter certain non-nuclear strategic attacks.¹⁸ Even if such threats are not intended to be executed, their availability weakens the reassurance value of NFU.

Third, NFU commitments lose credibility if they are seen as easily reversible. India’s already-caveated NFU policy, for example, has faced skepticism partly because officials periodically have suggested it could be revised.¹⁹ In China’s case, internal debates have at times emerged over whether its NFU commitment should be made conditional, although official policy appears to have rejected such changes.²⁰ More importantly, China’s proposed elements for an international NFU treaty include a withdrawal clause allowing a state to exit “if it determines that an extraordinary event related to this Treaty has endangered its supreme interests.”²¹ If interpreted as permitting withdrawal shortly before or during a conflict, such provisions could effectively nullify the value of the commitment. For any nuclear-armed state, maintaining a balance between permanence, which underpins credibility, and flexibility, which hedges against uncertainty, is inherently difficult.

Fourth, a deeper challenge lies in the human factor. Even a sincere peacetime commitment to NFU cannot guarantee behavior under existential threat. When confronted with imminent threats to core interests, decisionmakers may view nuclear escalation as a last resort offering a chance of survival. Expecting an adversary to believe that a state would categorically forgo such an option, even under extreme conditions, runs against basic assumptions about human behavior. Differences in how this challenge is perceived may also reflect deeper political and cultural traditions. The lingering influence of Communist thought, with its emphasis on the malleability of human nature, may lead some Chinese strategists to discount this constraint more than their American counterparts. Regardless, these underlying differences in assumptions about human behavior under extreme stress should be better understood, rather than interpreted as mere distrust of stated intentions or as an affront to one’s integrity.

Moving Beyond Debates About No-First-Use Credibility

Under conditions of ambiguity, concrete steps to align a declaratory NFU commitment with force structure by imposing tangible constraints on first use may be necessary to lend the commitment credibility. When China presses the United States to adopt NFU, its objective likely also extends beyond a change in U.S. declaratory policy to longer-term adjustments in U.S. nuclear forces themselves and how they are postured. Indeed, Chinese experts’ dismissal of the credibility of a potential U.S. NFU or sole-purpose policy, both of which were debated during the Barack Obama and Joe Biden administrations, suggests that Beijing places limited weight on declaratory policy alone.²² Conversely, U.S. assessments of China’s NFU credibility are increasingly shaped by China’s expanding nuclear capabilities. Yet neither side has clearly articulated what force structure would be consistent with a credible NFU declaration, either for itself or for the other. A substantive exchange of views, or ideally a joint study, on how a country could align force structure with NFU commitments would be a logical starting point for meaningful dialogue. During this process, Beijing could ask Washington what Chinese measures would increase U.S. confidence in China’s NFU commitment, while Washington could ask Beijing which U.S. measures would make an American NFU commitment credible should Washington choose to adopt one.

Even if Washington were to become interested in NFU, the issue becomes more complex if China maintains a categorical NFU policy while the United States adopts a conditional or targeted NFU approach toward China but not toward other adversaries. It would be difficult, for instance, for Washington to reach a similar NFU arrangement with Russia, given Moscow’s reliance on nuclear first use to offset conventional inferiority. In such a scenario, U.S. requirements to retain full-spectrum nuclear options against Russia would constrain how far it could adjust its force structure to align with an NFU posture toward China.

One possible way to mitigate this tension could be to shift the focus of force structure analysis from one’s entire nuclear arsenal to theater-range nuclear forces capable of striking the other side in a regional conflict. Because nuclear first use is most likely to arise from escalation of a regional conventional conflict, such as over Taiwan, aligning theater nuclear force postures in the West Pacific with an NFU framework could provide meaningful reassurance while preserving U.S. flexibility to address nuclear risks in other theaters.

Ambiguity surrounding how many of China’s medium- and intermediate-range conventional-nuclear dual-capable missiles are assigned nuclear missions contributes significantly to worst-case assessments in Washington.

Conceptually this sounds simple, but it would be difficult in practice. An initial step in this direction would be to enhance transparency regarding the deployment of theater nuclear forces in the West Pacific. While submarine-based systems would remain difficult to address, greater transparency about the scale and geographic distribution of land- and air-based systems within mutual strike range could reduce worst-case assumptions about capabilities and intentions. The United States does not currently deploy land- or air-based theater nuclear systems in the region, but potential future deployments, including systems based in Guam or allied territories, are already a source of Chinese concern. On China’s side, ambiguity surrounding how many of its large arsenal of medium- and intermediate-range conventional-nuclear dual-capable missiles are assigned nuclear missions also contributes significantly to worst-case assessments in Washington regarding China’s theater nuclear capabilities. The two sides could pursue targeted transparency measures applied specifically to such theater nuclear forces. They could also explore reciprocal restraint measures linking any future U.S. deployments, in scale, location, and posture, to corresponding limits on Chinese systems capable of striking U.S. regional targets, including those deployed within specified distances from China’s coastline.

Such initial steps could be backed by deeper exchanges, or a joint study, that would, at a minimum, help build shared understanding of the operational challenges in making NFU credible and reduce the tendency to interpret skepticism as evidence of bad faith rather than structural or operational difficulty.

North Korea’s expanding nuclear arsenal presents an additional complication. North Korea’s declaratory policy emphasizes early nuclear use in a conventional conflict. This reinforces U.S. incentives to retain first use options for theater nuclear forces in Northeast Asia. A clearer recognition of this challenge, potentially emerging from the joint U.S.-China study or exploration proposed above, could incentivize Beijing to address the North Korean nuclear issue more seriously. It would be in China’s interest, for example, to bring North Korea into a regional NFU understanding or agreement. Doing so would signal China’s commitment to advancing NFU at the global level and, if declaratory policy is matched by corresponding changes in force structure, could alleviate allied concerns about the North Korean threat and lessen their perceived need for forward-deployed U.S. nuclear assets, thereby contributing to greater stability in U.S.-China nuclear relations.

Finally, U.S. and Chinese strategists would need to consider how U.S. allies might react to a potential U.S.-China mutual NFU arrangement. To start, China would need to address their conventional security concerns. U.S. allies such as Japan and South Korea worry that NFU could embolden Chinese conventional aggression, particularly as U.S. conventional advantages in the region narrow. Rather than adopting a more assertive conventional military posture, China would need to demonstrate greater sensitivity to these concerns and show willingness to exercise restraint in its use or threat of force more broadly. Such steps are essential to creating the political conditions necessary for a more credible U.S.-China mutual NFU framework to become feasible.

For the United States and China, strategic stability has been both a point of convergence and a source of friction.²³ Conceptually, it offers promise but also generates persistent disagreement as the two sides seek a mutually acceptable framework to manage their nuclear relationship.

Friction arises primarily from divergent views on the scope and practical meaning of the concept. For the United States, strategic stability is largely defined in terms of maintaining nuclear deterrence stability. Chinese leaders, by contrast, are more concerned with perceived U.S. hostility toward the regime and other core interests, and they have consistently understood strategic stability as encompassing broader political and strategic issues rather than nuclear deterrence stability alone. For Beijing, the development and demonstration of nuclear capabilities can serve to remind Washington of the catastrophic risks of challenging China’s core interests, thereby stabilizing the broader relationship by encouraging U.S. acceptance of peaceful coexistence despite deep political and ideological differences. For example, the elevation of the PLA’s Second Artillery from a military branch to the Rocket Force as a full military service in 2015 reflects the broader geopolitical role assigned to the nuclear force, as evidenced by its mission statement’s emphasis on “strategic counterbalance.”²⁴

China’s accelerated nuclear buildup over the past decade has unfolded alongside heightened concern in Beijing over U.S. actions perceived as challenging regime security and territorial claims. In this context, while some U.S. security policymakers view strategic stability as reflecting the reality of mutual nuclear vulnerability, Beijing has not treated mutual nuclear vulnerability with Washington as merely a mechanism for addressing nuclear threats. This is evident in the fact that after it became known that Xi Jinping had directed the acceleration of nuclear modernization, there was no corresponding surge in Chinese expert analysis at that time suggesting that the U.S. nuclear threat had grown, let alone analysis advocating a large-scale nuclear buildup in response to such a threat.²⁵ Rather, mutual vulnerability is seen as a means to compel U.S. acceptance of peaceful coexistence, conceived as restraint from actions perceived to challenge China’s core interests, which had become a growing source of concern in Beijing.

Partly for this reason, China has at times appeared willing to intensify nuclear competition as a means of managing broader political tensions. In 2024, for example, China suspended U.S.-China nonproliferation and arms control talks by linking them to U.S. arms sales to Taiwan. This broader political dimension remains a central source of divergence in how the two sides conceptualize strategic stability.

These broader tensions have not entirely precluded Chinese experts from recognizing the value of a narrower conception of strategic stability centered on nuclear relations. However, broader political issues in the bilateral relationship have made agreement even on this narrower definition more difficult. In the Obama administration’s Nuclear Posture Review in 2010,²⁶ for example, Washington signaled a greater willingness than before to acknowledge the reality of mutual nuclear vulnerability with China. Yet within the U.S. strategic community, hesitation remained about explicitly committing to refrain from challenging China’s second-strike capability. This reflects concern that, under extreme conditions, the United States may need to retain the option of limiting damage by striking an adversary’s remaining nuclear forces if escalation is judged to be uncontrollable.

A bilateral conflict escalating into all-out nuclear war is regarded as plausible because of deep political tensions. These include perceived clashes over core values, rules, and norms. Such tensions reinforce the belief that the two sides are locked in a fundamental conflict of interests that could escalate into existential crises. These factors sustain interest within the U.S. strategic community in maintaining damage limitation capabilities against China that could undermine its second-strike capability. This highlights the limits of the American interest in pursuing nuclear stability without parallel efforts to address broader political tensions.

Measures to Narrow the Gap

There is a clear relationship between the narrow U.S. and broad Chinese conceptions of strategic stability. Narrowing the distance between them could be addressed through two complementary approaches. One is to reduce political disagreements, thereby lowering Beijing’s perceived need to link nuclear issues to the broader bilateral relationship. The other is to gradually isolate nuclear relations from the overall relationship as much as possible. While it is unrealistic to eliminate the influence of broader political tensions or completely isolate nuclear issues, prioritizing nuclear stability remains a meaningful objective that serves both sides’ shared interest in avoiding nuclear conflict and limiting arms racing.

The second Trump administration’s abandonment of the Biden administration’s framing of strategic competition between democracies and autocracies may reduce ideological confrontation and make it easier for Beijing to feel more secure.

On the first approach, the second Trump administration’s abandonment of the Biden administration’s framing of strategic competition between democracies and autocracies may reduce ideological confrontation and make it easier for Beijing to feel more secure. Its reduced willingness to assume existential risks on behalf of allies, along with a more transactional approach to Taiwan, suggests greater openness to accommodating what Beijing defines as its core interests. The outcome of the Trump-Xi summit in May 2026, including Trump’s decision to delay authorizing arms sales to Taiwan, appears consistent with this shift. Such developments could alleviate Chinese concerns about U.S. intervention on issues related to perceived territorial sovereignty. The Trump administration has also repeatedly emphasized the goal of maintaining “strategic stability” with China, including in official statements and key documents such as the National Defense Strategy.²⁷ At the May 2026 summit, the two presidents agreed to develop a “constructive relationship of strategic stability.” In these contexts, the term of strategic stability appears to reflect a broader conception of overall bilateral stability, closer to Beijing’s preferred framing. For Beijing, this shift could be seen as a positive development and could warrant a reassessment, and possible moderation, of its current position against discussing nuclear stability.

At the same time, improved overall relations could create space for both sides to partially disentangle nuclear issues from other aspects of the relationship. Given the difficulty of reaching agreement on explicitly acknowledging mutual nuclear vulnerability, it would be more productive for U.S. and Chinese policy communities to focus on narrowing the differences in how they conceive of nuclear stability. A practical starting point would be to deepen mutual understanding of the operational-level obstacles that impede steps to build nuclear stability. Both sides could start by examining how their own policies and practices have been interpreted by the other side and discouraged the pursuit of stabilizing measures.

From the U.S. side, despite rhetorical support for strategic stability, certain operational measures risk undermining it. A prominent example is the rollout of the Golden Dome missile defense program, with the declared intent to defend “the United States against ballistic, hypersonic, advanced cruise missiles, and other next-generation aerial attacks from peer, near-peer, and rogue adversaries.”²⁸ Beijing has criticized such developments, arguing that they “pose a severe damage to strategic stability” and “completely and utterly reject the core principle—that strategic offensive and defensive weapons are inseparable—which underpins global strategic stability.”²⁹

At the same time, it remains unclear whether recent U.S. missile defense policy reflects a coherent strategic shift aimed at neutralizing adversaries’ second-strike capabilities, or instead reflects aspirational goals shaped by presidential preferences that are disconnected from operational realities. Trump’s tendency to articulate ambitious but vague and insufficiently planned policy goals may have contributed to the incoherent rollout of the Golden Dome project. In practice, discussions within the U.S. strategic community suggest more modest expectations than those proclaimed by President Donald Trump, such as complicating limited adversary strikes and deterring coercive missile threats, rather than achieving comprehensive defense against major nuclear powers like China. This more limited conception is reflected in the rationale for homeland missile defense advanced by experts such as Robert Soofer, who now serves in a senior position in the administration and has emphasized deterring “limited coercive missile threats.”³⁰ Persistent skepticism within the U.S. policy community about the technological feasibility, cost, and strategic value of large-scale missile defense will also shape implementation. Given the risks of misperception and worst-case reactions, however, Washington has a clear interest in articulating a more coherent and realistic missile defense strategy that connects to its strategic stability aims. Track 2 dialogues could help clarify the actual scope and intent of these policies using publicly available information.

It is also in China’s interest to recognize that its own capabilities and policies have become part of the justification cited among some American proponents of the Golden Dome missile defense program. First, opacity surrounding China’s nuclear buildup, particularly the lack of explanation for the expansion of silo-based and road-mobile intercontinental ballistic missiles (ICBMs) capable of striking the U.S. homeland, fuels concern about Chinese deterrence objectives. Second, the perceived growing risk of a Chinese military attack on Taiwan heightens fears in Washington that China might consider a limited nuclear strike against the U.S. homeland to undermine U.S. resolve if a conventional conflict escalates. Third, reported development of conventional ICBMs suggests an increased risk of long-range strikes against the U.S. homeland, reinforcing perceived needs for defensive capabilities. Fourth, China’s continued rejection of any arms control or strategic stability engagement strengthens the view that its nuclear buildup is driven primarily by its own ambitions and is not responsive to U.S. policies or actions. Accordingly, some in Washington conclude that U.S. defensive measures like Golden Dome neither trigger an arms race nor jeopardize arms control efforts that Beijing has already declined. Finally, China’s pursuit of its own layered missile defense system, including strategic interceptors against ICBMs,³¹ raises doubts in Washington about the sincerity of Beijing’s criticism of U.S. missile defense programs.

These issues comprise a substantive agenda for both official and unofficial dialogues and could help both sides better understand how their actions shape the other’s interest in pursuing strategic stability measures.

For many years, the United States has advocated arms control dialogue and proposed near-term transparency and confidence-building measures. The Biden administration, for example, promoted missile pre-launch notification mechanisms and crisis communication channels, and signaled willingness to pursue reciprocal visits to nuclear testing sites. Trump also raised arms control with China, with his administration proposing a multilateral strategic stability dialogue more aligned with China’s stated preference than earlier trilateral arms control proposals.

China has tended to deflect U.S. overtures and insisted that the onus is on the United States (and sometimes Russia) to lower nuclear risks. However, in a changing international environment, Chinese experts have increasingly pointed to opportunities for China to play a larger role in advancing the global arms control agenda,³² with some arguing that a more proactive approach serves China’s own interests.³³ As China emerges as a leading military power, there may be less reason for Beijing to retain its traditional concern about being pressured into accepting unfavorable agreements in negotiations with a militarily superior adversary.

At the same time, China has formalized two high-level principles guiding its approach to arms control and disarmament: to “maintain global strategic stability” and to ensure “undiminished security for all.”³⁴ These are broadly appealing principles, but they have gained limited traction among other nuclear powers, likely because they have not been translated into concrete parameters capable of addressing specific security concerns. A useful next step, therefore, would be for the United States and China to jointly explore how these principles could be operationalized in practice. An initial effort could focus on two areas in particular: defining the conditions under which missile defense systems undermine strategic stability, and developing standards for assessing the security externalities that one state’s policies impose on others.

Defining “Global Anti-Missile Systems” That Undermine Strategic Stability

In official statements and documents, China appears to direct its opposition primarily at “global” missile defense systems, although it remains unclear which specific capabilities or programs Beijing understands as falling within that category. For example, Beijing has consistently expressed opposition to the deployment of “global anti-missile systems.” In some cases, China appears to focus on “global anti-missile systems that undermine strategic stability,” potentially implying that not all such capabilities threaten stability.³⁵ In others, it seems to imply that all global missile defense systems inherently threaten strategic stability.³⁶

This ambiguity probably reflects imprecise wording. In practice, China has likely adopted a broad position that any global anti-missile systems are inherently destabilizing. Even under this interpretation, important distinctions remain undefined. It is unclear how China differentiates between “global” anti-missile systems it opposes and other non-global forms of missile defense, including national and theater systems it appears more willing to tolerate, given the absence of a clear definition of what constitutes a “global” system. China’s emphasis on globality may suggest that its concern lies less with the geographic scope of the territory being defended than with the locations or the overall architecture of the deployment of relevant capabilities, including radars, satellites, and interceptors. In some instances, China has criticized the “unrestricted advancement of the ‘Golden Dome’ global anti-missile system,”³⁷ suggesting that certain constraints on such systems could make them more acceptable. At the same time, China is pursuing its own layered missile defense capabilities, including systems such as the HQ-29, often compared to U.S. systems like the SM-3 or even the Ground-Based Interceptor that is part of the U.S. limited national missile defense architecture.³⁸ This indicates that China does not categorically reject all strategic missile defense systems, but rather objects to specific configurations, scales, or modes of deployment.

A logical starting point for substantive engagement, therefore, is to develop shared understandings of which missile defense systems, which constituent elements, and which deployment patterns are perceived to undermine strategic stability. Given that this concern originates largely from the Chinese side, Beijing could take the lead by clarifying its definitions and criteria.

Several concrete questions could help structure such a dialogue. For example, how does China assess space-based interceptors—a key component of Golden Dome? Does it view all space-based interceptors as inherently destabilizing, or only those deployed at scale or in certain configurations? Does China envision a solution centered on banning deployment, or does it believe that restrictions should also extend to research, development, and manufacturing activities? Finally, what standards of verification does China consider necessary to make such measures credible and enforceable?

Another example is to examine which ground-based long-range interceptors should be considered “global anti-missile systems” that undermine strategic stability. Does the distinction between problematic and acceptable systems rest primarily on the scale of deployment, or should their performance capabilities also be considered? Where should a reasonable cutoff be drawn in terms of quantity and/or quality? If China views missile defense systems capable of providing large-area protection as destabilizing, while accepting point-defense systems, does this imply that all high-altitude, midcourse, long-range interceptors are inherently destabilizing given their capacity to protect large areas?

A related issue is whether regional missile defense systems may be considered part of a broader global anti-missile system that undermines strategic stability. On one hand, China’s opposition to “global anti-missile systems” appears focused on strategic, long-range interceptors, suggesting less concern about theater-level systems. On the other hand, Beijing reacted strongly to the 2016 U.S. deployment of the Terminal High Altitude Area Defense (THAAD) system in South Korea, arguing that it threatens “global strategic stability.”³⁹ If China views certain regional systems as destabilizing, greater clarity will be needed on which types of these shorter-range systems, including their deployment modes, raise such concerns.

As asymmetries in missile defense capabilities between the two countries narrow, the two sides should face fewer obstacles in jointly examining these operational-level issues.

Specifying Standards to Ensure “Undiminished Security for All”

The principle of “undiminished security for all” indicates a stated willingness to take into account the security interests of all relevant countries in defense planning and arms control efforts. In the Asia-Pacific region, a particularly urgent challenge is the intensification of regional missile competition with China at the forefront and many other countries accelerating their own missile investments. Given the urgency, severity, and multilaterally interactive character of this security challenge, it represents a high-priority case for examining how the principle of “undiminished security for all” could be operationalized in practice.

Across the Asia-Pacific region, from Russia and North Korea in the north to Australia in the south, countries are accelerating the development of theater-range missiles.

Across the region, from Russia and North Korea in the north to Australia in the south, countries are accelerating the development of theater-range missiles. Most are conventional, precision systems that serve as critical warfighting capabilities with strategic significance. China has expressed particular concern over Japan’s missile program, while closely monitoring developments in South Korea, Taiwan, and Australia, as well as the Philippines’ introduction of foreign missile systems. The United States remains China’s primary concern, with theater missiles under rapid development that could be deployed to regional bases or transferred to allies. Over time, these capabilities could shift the regional balance of conventional strategic power in ways unfavorable to China, despite its own rapid expansion and existing technological and numerical advantages in theater missile forces.

To reduce the risk of a destabilizing regional missile race, China could advocate for a multilateral dialogue to explore how the principle of “undiminished security for all” can be applied to the development and deployment of theater-range missiles. Historically, Beijing has pointed to shortcomings in the now-terminated Intermediate-Range Nuclear Forces (INF) Treaty to justify its non-participation in such U.S.-Russia missile constraints. Today, however, China has an opportunity to help shape new rules and norms that both address its security concerns and demonstrate its role as a constructive contributor to international security.

Specifically, China could invite regional actors, including Japan, South Korea, and the United States, for example, to begin a multilateral dialogue on what types of theater missiles threaten others’ security interests and therefore contradict the principle of “undiminished security for all.” Given the close geographic proximity of these countries, such discussions would also need to address acceptable standards for missile deployment, including basing locations and the patrol areas of mobile systems. Clarifying targeting policies could further help each other conduct realistic threat assessments.

For China, which has long been wary of stronger rivals imposing unfavorable rules, this presents an opportunity to take the lead in initiating and shaping shared rules at a time when relative capability advantages work in its favor.

Despite ongoing competition between China and the United States, important areas of shared interest remain. These stem in part from third-party activities and technological developments that could contribute to nuclear risks. Practical cooperation in these areas could help reinforce habits of restraint and foster global strategic stability.

One such area is the shared interest in keeping outer space free of nuclear weapons. Both the United States and China are parties to the 1967 Outer Space Treaty, which prohibits the deployment of nuclear weapons in space, and both have substantial strategic interests in maintaining a stable and accessible space environment. For China, these interests are particularly significant: It operates the world’s second-largest satellite constellation, serving both civilian and military functions, and has articulated ambitious plans to establish itself as a leading space power. Although strategic competition between the United States and China increasingly extends into the space domain, these underlying interests align Beijing with Washington and its allies in preventing the deployment and use of nuclear weapons in space, which would jeopardize all countries’ continued access to and use of that domain. Reported Russian efforts to develop nuclear anti-satellite (ASAT) capabilities, together with indications of North Korean interest in similar technologies, underscore the urgency of advancing cooperation around this shared interest.⁴⁰

At least two obstacles could hinder cooperation. The first is the possibility of future Chinese interest in nuclear ASAT technologies. Researchers at China’s Northwest Institute of Nuclear Technology, an institution with close ties to the PLA and a history of conducting work related to China’s nuclear weapons program, reportedly have conducted simulations to assess the performance of such systems in space.⁴¹ While this research could serve multiple purposes, including understanding potential threats to Chinese satellites or informing future decisionmaking, it leaves open the possibility of eventual capability development. Often heard Chinese concerns about security risks posed by foreign satellite constellations in low Earth orbit, such as those built by SpaceX, may reinforce incentives to retain a nuclear counterspace option. Even without any intention to develop or deploy such capabilities in the near term, keeping the option open (whether in fact or in the perception of others) could undermine international confidence in China’s commitment to prohibition.

A second obstacle is China’s reported testing of a Fractional Orbital Bombardment System (FOBS) in 2021, which many U.S. analysts interpret as enhancing China’s global nuclear strike capability. Although publicly available information remains limited, U.S. assessments treat this development as serious and significant. The Defense Intelligence Agency, for example, projected in 2025 that China could deploy sixty FOBS by 2035.⁴²

If pursued, such a capability could complicate efforts to reinforce norms against nuclear weapons in space. A FOBS shares key characteristics with a nuclear co-orbital ASAT system, particularly in its method of delivery: Both involve placing a nuclear payload into orbit via a ballistic missile. A co-orbital ASAT could remain in orbit for extended periods and maneuver toward a target before detonation, whereas a FOBS, if intended to avoid violating the Outer Space Treaty, would remain in orbit only briefly before reentering the atmosphere to strike a target.

In practice, however, these distinctions may be difficult to verify. A nuclear ASAT could detonate before completing a full orbit, while a FOBS could remain in orbit longer than expected before deorbiting. Such overlap in operational profiles complicates efforts to distinguish between the two systems based solely on observable behavior, creating challenges for transparency and verification.

Measures to Keep Space Nuclear Weapon Free

It remains plausible that the first obstacle—potential Chinese interest in space nuclear capabilities—can be avoided or overcome. China has historically explored new military technologies that it ultimately did not develop or deploy. Chinese security experts also appear uneasy about Russia’s reported interest in space-based ASAT weapons. Given China’s growing stake in maintaining reliable access to outer space, there is a meaningful possibility that it could align with other countries in strengthening international norms against nuclear ASAT weapons. These norms include the well-established prohibition on co-orbital nuclear ASAT systems, which involve placing nuclear weapons in space and therefore violate the Outer Space Treaty, as well as the less developed norm against direct-ascent nuclear ASAT systems, which are not explicitly prohibited under the Treaty.

The second obstacle may be more difficult to address. Despite rising concern in Washington about China’s reported development of FOBS, Beijing initially rejected the accusation in 2021, describing the event as a routine space vehicle test, and has not provided further clarification. At the same time, the officially described DF-5C ICBM capability of “global coverage in terms of strike range”⁴³ has fueled speculation that it could strike the U.S. homeland via a south polar trajectory, potentially through a FOBS-like configuration, as suggested in the Defense Intelligence Agency’s 2025 assessment.⁴⁴

Even if China is pursuing such a capability, there are no public reports indicating that it has become operational as of 2025, leaving room for external influence or negotiation over the ultimate decision to deploy the capability and the scale of any eventual deployment. Encouraging restraint will require U.S.-China dialogues, both official and unofficial, to focus on two issues. The first is to raise Chinese awareness of U.S. threat perceptions. Many U.S. strategists view FOBS as particularly destabilizing because of their ability to strike critical targets, including national leadership and nuclear command, control, and communications (NC3) hubs, with limited warning, potentially bypassing early warning systems and reducing defensive response options. These concerns are often interpreted as indicating a possible Chinese interest in surprise attacks against leadership and NC3.⁴⁵ Some civilian Chinese experts have viewed such concerns as “far-fetched and somewhat paranoid,”⁴⁶ and it is likely that the PLA has even less appreciation of the threat perceptions the United States has developed regarding such weapons.

A perception gap over whether FOBS could serve defensive or offensive purposes has reinforced U.S. domestic support for expanded homeland missile defense.

The second issue is the need to better understand action-reaction dynamics between Chinese and U.S. policies. If China is developing FOBS, a likely motivation is to circumvent U.S. homeland missile defense by enabling strikes from the south, where current defenses have a significant gap. However, a perception gap over whether FOBS could serve defensive purposes (deterrence by retaliation) or offensive purposes (escalation advantage) has reinforced U.S. domestic support for expanded homeland missile defense, with Golden Dome as the latest manifestation.⁴⁷ From Washington’s perspective, China’s development of FOBS appears to have emerged at a time when U.S. missile defense capabilities have remained limited and evolved incrementally, weakening the defensive rationale that such a capability is to offset U.S. missile defenses and preserve strategic deterrence. As a result, FOBS is increasingly interpreted as part of a broader Chinese nuclear buildup intended to alter the strategic balance, reinforcing concerns about more aggressive strategic intent.

In China, experts often cite long-standing hawkish voices in the United States that advocate more expansive missile defense capabilities to justify China’s own responses, even though these views did not become official U.S. policy. This underscores the importance of ensuring that defense planning is guided by a balanced assessment of an adversary’s official policies and capabilities rather than by its most hawkish domestic voices. Greater Chinese awareness of how its own capability development, including FOBS, may reinforce U.S. countermeasures, including expanded missile defenses and nuclear capabilities, thereby weakening rather than strengthening China’s long-term deterrent, could also encourage reconsideration of its current approach. Increased transparency regarding the prospective role of FOBS, and the place of the broader nuclear buildup within China’s overall deterrence strategy, can be a useful first step toward mitigating these dynamics.

In a more adverse scenario, if Washington becomes increasingly pessimistic about preserving the norm against nuclear weapons in space and more concerned about potential advantages gained by Russia, China, or North Korea, a decision to develop comparable U.S. capabilities is easily imaginable, much as Washington has signaled willingness to resume nuclear testing on an equal basis in response to rumored nuclear testing by its rivals. During the Cold War, the United States and the Soviet Union successfully agreed to ban FOBS, suggesting that a similar agreement involving the United States and China may still be possible before such dynamics intensify.

Expert-level discussions can also begin to examine how any future agreements could be made credible through verification. Under SALT II, the United States relied on national technical means to monitor Soviet FOBS deployment and dismantlement, aided by the fact that these systems were deployed on fixed ICBMs in identifiable silos. If China were to deploy FOBS in DF-5C silos, similar monitoring approaches could be feasible.

The more difficult challenge is verifying the absence of nuclear payloads on road-mobile missiles or civilian launch vehicles for use in space ASAT or FOBS roles. If countries with shared interests seek to prevent nuclear weapons in space, they could start by jointly assessing the feasibility of verification. Experts from the United States, China, and other interested countries could examine potential verification and confidence-building measures, including both pre-launch and in-orbit approaches. Given the technical, logistical, and security complexities involved, early engagement is essential. A mechanism similar to the UN Group of Scientific and Technical Experts on Nuclear Disarmament Verification could serve as a model for such multilateral collaborative efforts.

Preventing nuclear proliferation has long been an area of shared interest between Washington and Beijing. China closely and warily monitors domestic debates in South Korea and Japan over nuclear weapons, although political considerations have led Beijing’s public pressure to focus significantly more on Japan. In the United States, despite discussions in some quarters of the U.S. expert community about the possible merits of “friendly proliferation,” including comments by Undersecretary of Defense for Policy Elbridge Colby prior to taking office,⁴⁸ the Trump administration has not pursued such an approach. Strong domestic voices opposing “friendly proliferation”⁴⁹ suggest likely continuity with previous administrations in concerns about additional countries, including allies, acquiring independent nuclear capabilities.

Nonetheless, major shifts in the global geostrategic environment, including Russia’s invasion of Ukraine, China’s rise and nuclear expansion, and declining perceptions of U.S. commitment to allies, are increasing proliferation risks, particularly in East Asia. Several factors contribute to this trend.

North Korea’s expanding nuclear capabilities are a direct driver of pro-nuclear sentiment in South Korea and Japan, especially as many regional actors have tacitly accepted Pyongyang’s de facto nuclear status. Russia now considers denuclearization of North Korea a “closed issue.”⁵⁰ China has largely stopped mentioning denuclearization of the Korean Peninsula in its official statements and government documents since around May 2024. The current government in South Korea has prioritized diplomatic engagement over pressing Pyongyang on denuclearization. Meanwhile, the Trump administration, influenced by shifting regional positions and the possibility of renewed engagement with Kim Jong Un, has remained relatively muted on the issue, leaving policy direction ambiguous. In the meantime, North Korea’s arsenal continues to expand in size and diversity, aided by the erosion of the UN sanctions regime and growing defense cooperation with Russia following Pyongyang’s support for Moscow’s aggression against Ukraine.

China’s own security policies, whether intentional or incidental, have also heightened concerns in Japan and South Korea, although such concerns are expressed more openly in Tokyo than in Seoul. Nuclear-related disputes have significantly raised South Korea’s threat perception toward China since 2016, when Beijing applied unprecedented coercive pressure in response to the deployment of a U.S. THAAD missile defense system in South Korea, with Chinese experts citing concerns over its impact on China’s nuclear deterrent. South Korean experts often acknowledge privately that China’s growing military capabilities and increasingly assertive posture are fueling domestic debate about future security options.

In Japan, concerns are more visible and have intensified as bilateral relations with China deteriorate. Tokyo has long worried that a U.S.-China mutual nuclear deterrence relationship could embolden China’s conventional military aggression toward neighboring countries and weaken the credibility of U.S. extended deterrence. China’s nuclear buildup, combined with its broader military expansion in the past decade, has further heightened these concerns, particularly as Beijing appears increasingly willing to make Japan an example of the consequences of defying China.

A related factor is the risk of conflict over Taiwan, which underpins deteriorating China-Japan relations and broader regional security adjustments. As long as the possibility of a major conflict remains, driven by Beijing’s refusal to renounce the use of force to unify Taiwan, regional actors face pressure to prepare for high-intensity war. This dynamic makes it extremely difficult to contain arms competition. As the security environment deteriorates and confidence in U.S. security commitments weakens, interest in hedging strategies, including potential nuclear options, has grown.

Developing Coherent Policies to Contain Proliferation

Neither Washington nor Beijing appears to prioritize long-term nonproliferation over near-term geostrategic interests. This results in policy ambiguity on the U.S. side and incoherence on the Chinese side.

A growing point of contention is U.S. extended nuclear deterrence. China has significantly intensified its criticism of such practices in recent years, at times targeting the concept itself, but more often directing its critique specifically at the United States. This marks a shift from earlier private acknowledgments by Chinese experts that U.S. extended nuclear deterrence helps discourage allied proliferation. Beijing’s evolving position risks working against its own interests, given that the most immediate proliferation pressures in China’s neighborhood arise from U.S. allies.

This tension likely reflects China’s concern that the United States may use extended nuclear deterrence to justify forward deployment of nuclear capabilities near China, including on allied territory, or potentially establish new nuclear-sharing arrangements with regional allies as part of efforts to counter Beijing. The result is a deeper perception gap: Washington and its allies worry that Beijing is shifting the regional military balance, including in tactical nuclear capabilities, to enable coercion, while Beijing views U.S. policy as moving toward a more aggressive regional nuclear posture. As discussed earlier, greater transparency regarding each other’s theater nuclear forces could be a first step toward narrowing this gap.

Expert communities can also play a role in reducing misperceptions. In the case of Japan, Takaichi Sanae’s administration appears focused on strengthening the credibility of U.S. extended nuclear deterrence rather than pursuing an independent nuclear capability, a policy that has long served Chinese security interests. Although Tokyo is introducing some ambiguity regarding the three non-nuclear principles, this appears primarily linked to potential adjustments to the “no introduction” principle. The purpose may be to accommodate transit through Japanese waters by U.S. submarines that may carry nuclear weapons, such as after the introduction of the nuclear-armed sea-launched cruise missile, or SLCM-N, for contingency deployment. Such arrangements would not be unprecedented, as similar practices occurred during the Cold War under the “neither confirm nor deny” policy. As already pointed out,⁵¹ one potential motivation for the current Japanese government to consider formally updating the no-introduction policy is that advances in open-source research tools and technologies have made it much harder to conceal such visits than during the Cold War. A formal policy adjustment could therefore reduce the inconsistency between declaratory policy and practice. Importantly, there is no indication of intent to revise the principles of non-production or non-possession of nuclear weapons. The gap between this reality and Chinese criticism of Japan’s potential pursuit of nuclear weapons reflects a broader perception disconnect. Rather than fueling tensions, experts from the relevant countries can help better inform policymakers and the public through more nuanced policy analysis.

More broadly, attacking the concept of extended nuclear deterrence may be counterproductive. Globally, more states are becoming involved in such arrangements. Beyond U.S. alliances, Russia has extended nuclear guarantees to Belarus, the United Kingdom and France are exploring expanded assurances to European partners, and Pakistan may be experimenting with informal guarantees to Saudi Arabia. A more pragmatic Chinese approach would be to recognize the role of U.S. extended deterrence in limiting allied proliferation, while pursuing reciprocal transparency and restraint with the United States on theater nuclear forces in the Asia-Pacific. Such measures could be more productive in reducing incentives for future U.S. theater nuclear deployments or nuclear sharing arrangements between Washington and allies in the region.

China’s differentiated approach toward South Korea and Japan may also carry unintended risks. South Korea exhibits stronger public support for indigenous nuclear weapons, more open elite advocacy, and is pursuing nuclear-powered submarines alongside enrichment and reprocessing capabilities, which is widely seen as a hedge. The establishment of South Korea’s new Strategic Command has likewise sent an important signal and highlights the contrast between Seoul and Tokyo’s approaches. Yet Beijing’s response to these developments has been muted compared to its criticism of Japan. Admittedly, Japan is more advanced than South Korea in enrichment and reprocessing capabilities and possesses a large stockpile of reactor-grade plutonium. Yet in terms of demonstrated political will and efforts to create conditions for a future policy shift, Japan still trails South Korea. Nonetheless, on nuclear-powered submarines, Beijing has merely called on Seoul to “manage the issue prudently,”⁵² while issuing an official working paper urging Japan not to pursue such a capability,⁵³ even though Japan has no such policy in place yet. China’s differentiated approach suggests that it prioritizes drawing a U.S. ally closer to Beijing over constraining nuclear hedging, and may reflect a judgment that pressuring a relatively China-friendly U.S. ally over proliferation-sensitive activities would undermine the broader objective of weakening the U.S.-led security alliance.

This approach, however, could create a window for South Korea to manage major powers’ opposition to its nuclear hedging at a safe level by maintaining political balance and avoiding a clear alignment with either Washington or Beijing. Over time, this dynamic could enable South Korea to develop an increasingly advanced nuclear breakout capability. It is unclear whether Beijing has fully considered the long-term implications, particularly if South Korea’s progress encourages Japan and others to pursue indigenous nuclear options. At the same time, China faces a growing tension between advocating diplomatic solutions to address the threat perceptions underlying North Korea’s nuclear program and seeking to compel Japan, through coercive pressure, to forgo consideration of nuclear options. Yet coercive pressure directed at Japan, a country facing a less credible U.S. security guarantee, growing concern over North Korea’s expanding nuclear arsenal, unresolved territorial disputes with Russia, and the challenge of an increasingly powerful and adversarial China, may instead strengthen domestic arguments in favor of considering the previously unthinkable. In doing so, it risks increasing Japan’s long-term interest in nuclear proliferation, the very outcome Beijing seeks to prevent.

Advancing Nonproliferation Through Credible Negative Security Assurances

To strengthen the nonproliferation regime, China has in recent years promoted “early negotiations on and conclusion of an international legal instrument on unconditional negative security assurances to non-nuclear-weapon states.”⁵⁴ This proposal could offer a useful opportunity to address the security concerns of non-nuclear-weapon states in the Asia-Pacific.

Since Russia’s invasion of Ukraine and the violation of the Budapest Memorandum, any future agreement on negative security assurances will need to more directly address what happens if a nuclear-armed state violates its commitments. In Northeast Asia, for example, if North Korea were to use or threaten to use nuclear weapons against South Korea or Japan, would China, the United States, and Russia intervene? Without clearer answers, non-nuclear-weapon states in the region are unlikely to see strong value in negotiating a legally binding agreement. A regional dialogue on these questions could serve as a constructive first step toward addressing their security concerns and reducing incentives for proliferation.

What constitutes a “threat” of nuclear use? As Russia’s nuclear saber-rattling during the Ukraine war illustrates, explicit statements are not necessary to generate a perceived nuclear threat.

China’s concept of negative security assurances also includes a commitment not to use or threaten to use nuclear weapons against non-nuclear-weapon states.⁵⁵ Any negotiation of a legal instrument along these lines would therefore need to address a key definitional challenge: What constitutes a “threat” of nuclear use? As Russia’s nuclear saber-rattling during the Ukraine war illustrates, explicit statements are not necessary to generate a perceived nuclear threat.⁵⁶ A wide range of signaling activities during a crisis—such as raising nuclear alert levels, conducting exercises involving nuclear forces, testing nuclear-capable delivery systems, or showcasing nuclear capabilities through military parades—can send messages of potential nuclear use.

The international community has made little progress in addressing this issue, despite its central importance to the credibility of negative security assurances. China’s proposal provides an opportunity to initiate a more substantive discussion. The United States and its allies should engage constructively by proposing expert-level dialogue to exchange perspectives on the requirements for credible negative security assurances, identify areas of convergence, and clarify points of disagreement. Such dialogue would also offer a practical way to gauge each party’s seriousness in advancing meaningful progress.

By embracing “peace through strength” and dismissing the severity of perception gaps or the value of communication in narrowing them, both Beijing and Washington risk missing remaining opportunities to avoid an increasingly unmanageable deterrence spiral. Chinese decisionmakers have likely authorized the nuclear buildup assuming China’s self-perceived defensive intent would be understood, with insufficient appreciation of how these developments shape U.S. threat perceptions. In turn, if U.S. responses are designed primarily to maximize fear and uncertainty in Beijing, they risk reinforcing existing Chinese perceptions of American aggressiveness rather than sensitizing China to genuine U.S. concerns, strengthening arguments within China for further nuclear expansion.

Across the issues examined in this paper, from nuclear deterrence objectives and no-first-use to strategic stability, missile defense, space security, and regional proliferation, the pattern is consistent: Perception gaps, doctrinal ambiguity, and reciprocal responses based on worst-case assumptions are generating a self-reinforcing competition. These dynamics are also beginning to spill outward by increasing incentives for other regional actors to consider their need for nuclear weapons.

Yet the analysis also reveals how much practical convergence is latent within existing national positions. That convergence could be translated into targeted, constructive steps: internal policy studies to prioritize preventing nuclear use over seeking escalation advantages; joint operational studies on the credibility requirements of no-first-use and their alignment with force structure; reciprocal transparency and restraint linking any future U.S. forward deployment of theater nuclear forces in the Western Pacific to corresponding limits on Chinese systems within strike range of regional targets; clearer Chinese definitions of destabilizing “global anti-missile systems” and operational standards for applying “undiminished security” to theater missile competition involving Japan, South Korea, and others; expert work on verifying restrictions against nuclear ASAT capabilities before deployment decisions harden; and reducing proliferation pressures among U.S. allies through more credible negative security assurances, including deeper examination of what constitutes nuclear “threats” beyond explicit statements.

The May 2026 summit’s commitment to “a constructive relationship of strategic stability” offers a hopeful, if still ambiguous, opening. Translating that aspiration into practice demands sustained, operationally serious dialogue: One that scrutinizes the coherence and consequences of each side’s own policies, clarifies perceptions and constraints, and tests specific ideas for practical, reciprocal restraint.