What Are China’s Nuclear Weapons For?

The Ambitions Behind Expansion

Ashley J. Tellis

The recent expansion of China’s nuclear arsenal has been a striking feature of its progress toward great-power status. Even during the most intense periods of Cold War rivalry, Beijing maintained a small and remarkably vulnerable nuclear force that probably did not exceed 200 warheads. Although Chinese nuclear modernization continued after the Cold War ended, it has truly accelerated only over the last decade or so—with Beijing more than doubling the number of warheads deployed since 2020.

Given that this expansion is occurring when the U.S. and Russian arsenals are still constrained by the New START Treaty’s numerical limits, intense nuclear arms races have receded in international politics, and the inventories of the secondary nuclear states are either frozen or growing only incrementally, China’s motivations may seem somewhat puzzling. Tong Zhao’s recent essay in Foreign Affairs (“The Real Motives for China’s Nuclear Expansion”) represents an important contribution to our understanding of them. Zhao argues that China’s nuclear expansion is driven by Chinese leader Xi Jinping’s fundamental belief that nuclear weapons are distinctive instruments for “showcasing Chinese power” in the face of a United States that “has become increasingly hostile to Beijing.” China’s evolving nuclear forces are, accordingly, oriented toward serving a “strategic counterbalance” mission, which Zhao says aims to compel “the United States to take a more accommodating stance toward China.” Consequently, deploying “a larger nuclear arsenal would force Washington to genuinely respect Beijing and tread more cautiously” both in peacetime and during a crisis.

Although Zhao seems skeptical of this reasoning—such beliefs are “probably more a product of intuition than of rigorously examined logic and evidence”—the conviction that strong nuclear capabilities serve to protect a nation’s fundamental interests has been widespread since the beginning of the nuclear age. That Beijing would be focused on shaping U.S. perceptions of the balance of power to advance its interests at a time when China might have to deter the full might of American military dominance in various regional contingencies—most important, a crisis involving Taiwan—should not be surprising. It may suggest that Chinese leaders are actually quite rational and recognize that capable nuclear forces provide them with the ultimate backstop in any future confrontations with the United States. Zhao’s analysis subtly underscores this basic point: despite the understandable interest of China’s professional military officers in “war preparation” and “winning strategic victories,” a “persistent opposition to [nuclear] warfighting” still obtains, and China’s leaders continue to see nuclear weapons primarily as political instruments that bestow on their possessors “general leverage” in competitive circumstances, “especially given rising tensions with the United States.”

This conclusion is important—and fundamentally correct. But Zhao’s further claim that China’s nuclear modernization is “driven more by a nebulous political mandate than by distinct military necessity”—which includes “the lack of well-defined and thoroughly examined military objectives”—is more puzzling. To be sure, Chinese decision-making about many aspects of its nuclear transformation is opaque. Yet the notion of a “strategic counterbalance” mission suggests that, because rivalry with the United States is likely to become the defining feature of China’s strategic environment for as long as can be anticipated, Beijing will proceed steadily toward something resembling nuclear parity. This may entail either eventually seeking numerical equality with frontline U.S. nuclear forces or simply settling for some kind of “strategic equivalence” with the U.S. nuclear deterrent.

Where Beijing will ultimately end up is unclear, but the expectation of an intensifying antagonism with the United States seems to be leading China toward building up its nuclear capabilities across the board on the assumption that matching its rival as closely as possible will be necessary to protect Chinese interests in the face of overwhelming American power. Votaries of rational deterrence theory would not be surprised by this outcome.

China’s ambition of countering current U.S. nuclear superiority involves more than just an expansion in numbers of weapons. Beijing is focused, as well, on the acquisition of diverse technologies and is institutionalizing unprecedented changes in force posture that will enable it to meet specific operational goals in the nuclear realm. A careful examination of this effort, consequently, does not corroborate Zhao’s contention that Beijing largely views “nuclear weapons as symbols of military strength” rather than as a means “to achieve clearly defined military objectives, such as deterring an enemy from undertaking specific military activities.”

AIMING HIGH

The available evidence about China’s nuclear transformation suggests that it has four specific military objectives. First, Beijing seeks to increase its force survivability. The numerical enlargement of China’s warhead inventory and the diversification of its delivery systems, including the creation of a full-fledged nuclear triad, are driven by the objective of increasing the survivable fraction of the Chinese nuclear deterrent—that is, the number of Chinese weapons that would survive even a comprehensive first strike launched by the United States. Chinese military planners have a healthy appreciation for U.S. conventional and nuclear capabilities, as well as the vulnerability of their own deterrent in the past.

In an era of rising competition, Beijing’s desire to prevent Washington from ever concluding that it could “win” a nuclear war by executing “splendid first strikes”—those that could successfully neutralize China’s nuclear reserves—has taken on a new urgency. China has therefore sought to concurrently increase the number of nuclear warheads it deploys, diversify their modes of deployment and delivery, and alter its force posture through increased alert rates that would permit it to inflict immense damage on American cities and other targets, even after suffering a U.S. first strike. These transformations are not intended to support fighting a nuclear war—at least not yet—but to bolster strategic deterrence so that China’s emerging ability to inflict widespread “unacceptable” damage on U.S. targets would prevent Washington from ever contemplating nuclear attacks on China to begin with.

Second, Beijing seeks to increase its retaliatory effectiveness. Chinese leaders and military planners understand all too well that successful nuclear deterrence against the United States ultimately requires that China be able to hold at risk a variety of highly valued U.S. assets, even in the face of determined efforts to defend them. At the moment, U.S. national missile defenses are thin and would likely be ineffective against the threats posed by the offensive forces of a major nuclear power such as China. But as U.S.-Chinese competition evolves, Beijing cannot count on U.S. strategic defenses remaining underdeveloped in ways that give its offensive nuclear operations a free ride. Accordingly, China is investing heavily in increasing the ability of its nuclear weapons to penetrate U.S. defenses, even if those defenses become more sophisticated in the years ahead. Whether it is through the deployment of ever more sophisticated penetration aids (such as decoys, jammers, and maneuvering reentry vehicles) or the development of unconventional delivery platforms (such as hypersonic glide vehicles or fractional orbital bombardment systems), it aims to ensure that it can perpetually defeat any U.S. strategic defenses.

China wants the capacity to respond symmetrically to U.S. nuclear attacks.

Third, Beijing seeks to increase its escalation competitiveness. Given the crises China anticipates, it wants the ability to match the United States at every level of nuclear use. China’s transformation of its nuclear weapons inventory through the deployment of low-yield warheads (which could be supplemented by variable-yield weapons in the future) suggests that its military planners have recognized the challenges of facing up to an advanced nuclear threat such as the United States. Given the flexible yields of many U.S. nuclear weapons—that is, the option to reduce their explosive power—Chinese strategists want to avert a contingency in which the United States could use low-yield nuclear weapons to inflict discrete or limited damage on China and leave Beijing with only the problematic alternative of conducting major retaliatory attacks in response.

Because China wants the capacity to respond symmetrically to even small U.S. nuclear attacks—thus putting the onus for further escalation on the United States—its force transformation has now included the deployment of low-yield warheads that it had previously eschewed. These capabilities still do not appear to be directed toward true nuclear warfighting (as U.S. and Soviet tactical nuclear forces were during the Cold War). Rather, they seem to be centered on giving China the option of responding to U.S. limited nuclear attacks with comparable responses to render such strikes ineffective.

Fourth, Beijing seeks to increase its regional targeting effectiveness. As part of its contingency planning, it aims to hold at risk various Indo-Pacific countries that either threaten it directly or might make common cause with Washington against it. That China has continued to improve its theater nuclear systems (those intended to target its Asian neighbors and U.S. military forces operating in its vicinity), even as it has dramatically increased its strategic delivery vehicles—both land- and sea-based intercontinental ballistic missiles—aimed principally at the continental United States, suggests it is acutely aware that it is surrounded by significant nuclear threats, such as India and even Russia, and by a number of U.S. allies whose military facilities are critical for the success of U.S. combat operations against China.

For the understandable reason of bolstering deterrence, China has procured, and continues to develop, a variety of shorter-range nuclear weapons systems directed at important regional targets, including in U.S.-allied countries, such as Australia, Japan, and the Philippines, that are not nuclear powers themselves. An important aspect of Beijing’s nuclear transformation, therefore, is deterring any neighbors who directly or indirectly threaten China with significant conventional or nuclear forces, as well as any forward-deployed and -operating U.S. forces that could be used to attack China or undermine its core interests.

BALANCE OF POWER

The evidence suggests that Beijing is pursuing specific military-technical objectives as a logical complement to Xi’s political ambition of achieving a “strategic counterbalance” vis-à-vis the United States. These goals appear to be thought through carefully within the broader political framework of nuclear peer competition with the United States. China’s current military-technical initiatives, however, are still not intended for nuclear warfighting, but for bolstering deterrence. That is, Beijing, at least for now, does not plan to neutralize the U.S. nuclear force by preventive or preemptive attacks, as the Soviet Union did after it achieved nuclear parity; rather, it seeks to prevent Washington from using its superior conventional and nuclear capabilities to coerce or defeat China in any high-stakes confrontations in which vital Chinese interests are at risk.

Accordingly, Beijing’s new nuclear capabilities are not only appropriate investments for China, given its desire to defang “the existential threat that it perceives is coming from the United States,” but they also dovetail perfectly with Xi’s ambition of “achieving a more advantageous balance of power” vis-à-vis Washington. It would be a major miracle if Xi could achieve the latter objective without consciously integrating the operational aims pursued by Chinese military planners and which distinguish China’s current nuclear force transformation. Some elements of this effort may seem perplexing, but it is hard to dismiss the overall endeavor, as Zhao does, as “motivated by ambiguous political reasoning and muddled thinking.”

Concluding that China’s ongoing nuclear force transformation is far more rational, purposeful, and goal directed than Zhao gives it credit for does not imply that the United States must respond to it with a frenetic nuclear expansion of its own. Although China is impressively improving its nuclear forces, today they are still substantially inferior to those of the United States. Washington has time to take the appropriate measures. For the moment, the priority should be to complete its ongoing nuclear modernization program while making every effort to discuss issues of nuclear stability with China. Not surprisingly, Beijing has displayed little interest in pursuing such a conversation while it builds up its own nuclear arsenal. The fact that China’s nuclear transformation is driven by deep structural imperatives—the prospect of intensified competition with a much more powerful adversary such as the United States—should temper expectations that Washington and Beijing will be able to exit the nuclear cul-de-sac they find themselves in merely through dialogue.

Zhao Replies

I appreciate Ashley Tellis’s thoughtful response to my essay and welcome broader debate on the motives of China’s nuclear buildup. In my essay, I suggested that China’s recent nuclear buildup is driven more by a directional mandate from the political leadership than by a new doctrine shaped by military strategists. Xi views nuclear weapons as having excessive coercive power beyond the military realm—prompting and propelling a nuclear expansion that lacks clearly defined military goals and suffers from internal disorientation and incoherence. This is where I disagree with Tellis: China’s new nuclear capabilities certainly have military utility, but none of the military goals that Tellis noted explains the buildup’s timing, scale, or scope.

For example, the People’s Liberation Army has for decades been intent on enhancing the credibility of its second-strike capability. But China’s abrupt nuclear expansion goes far beyond what is necessary for that purpose. Just a few years ago, leading PLA nuclear experts deemed the U.S.-Chinese nuclear deterrent relationship “rather stable,” given the absence of significant expansion (or plans for expansion) of U.S. nuclear and nonnuclear strategic capabilities; accordingly, only incremental modernization was needed to counter U.S. technological developments.

Nor does the PLA’s desire for escalation-management capabilities explain the expansion. While that push has likely fueled the expansion of precision theater-range nuclear forces, it cannot explain extraordinary investments in hundreds of new silos for intercontinental ballistic missiles or its considerable expansion of road-mobile ICBMs. This growth in strategic nuclear forces is the most puzzling part of China’s nuclear buildup. Notably, these weapons would play no direct role in managing escalation in a regional war over Taiwan.

Tellis further suggests that one of China’s military goals is to deter “significant conventional” threats by targeting nuclear weapons against nonnuclear weapons states such as Australia, Japan, and the Philippines. Yet there is little evidence in China’s official documents or in private analyses by its experts to support this claim—and I generally find Tellis’s criteria for validating or refuting various claims about the PLA’s military goals unclear. Without examining internal deliberations and policymaking processes, such speculation often remains quite subjective.

Policymakers should be wary of assuming flawless internal policy logic or coherence when analyzing China’s nuclear strategy.

Tellis asserts that its “strategic counterbalance” mission will allow China to match U.S. nuclear capabilities “as closely as possible.” But the supposed need for nuclear parity cannot be derived from military-technical calculations of nuclear sufficiency. Instead, it rests on intuition, since the goal of strategic counterbalance is too vague to permit a quantitative analysis of needed warheads. Recognizing that China’s nuclear policy is guided by the nebulous concept of strategic counterbalance affirms that it is driven more by political than military objectives. Xi may or may not share Tellis’s understanding of which nuclear capabilities meet the goal of strategic counterbalance. Such inherent uncertainty is why a politically driven Chinese nuclear policy presents a more complex challenge than one driven primarily by military-technical considerations.

The United States has long experience tackling nuclear threats and is accustomed to devising military-technical solutions for given security problems. It knows how to deter aggression when an adversary’s military objectives are clear. Yet China’s are not. Accordingly, grasping the nuclear challenge requires comprehensive understanding of how internal changes in the Chinese system are reshaping Beijing’s traditional nuclear thinking. This evolution has led to growing inconsistencies and tensions in a nuclear doctrine developed in a centralized, stovepiped system in which political loyalty often trumps technical rationality. It is not hard to see how China’s “ambiguous political reasoning and muddled thinking” have led to significant blunders, on everything from “zero COVID” to the crackdown on high-tech industries. I wish I shared Tellis’s optimism that China’s nuclear policy goals are “thought through carefully,” but the evidence suggests that policymakers should be wary of assuming flawless internal policy logic or coherence when analyzing China’s nuclear strategy.

To point out the political drivers behind China’s nuclear buildup is not to justify it. Nor is my essay a call for the United States to remain passive in the face of China’s expansion. Rather, it urges Washington to avoid defaulting to worst-case-scenario thinking and to strive for the most realistic threat assessments possible. Here, I disagree with experts who downplay the importance of exploring the motivations behind China’s nuclear expansion, believing that only the results matter. Understanding those motivations is essential to anticipating future nuclear development, deployment, and employment strategies, as well as Beijing’s potential responses to U.S. countermeasures.

Such understanding will also allow policymakers to craft more effective diplomatic strategies for engaging China on nuclear risk reduction. A nuclear expansion driven by political objectives may offer more opportunities for Washington to influence China’s future nuclear development, explore agreements on nuclear restraint, and reduce the risk of misinterpretation and overreaction. Indeed, disentangling nuclear competition from political rivalry is an urgent task, and understanding China’s thinking is the crucial first step.