China’s Misunderstood Nuclear Expansion

Among the many issues surrounding China’s ongoing military modernization, perhaps none has been more dramatic than its nuclear weapons program. For decades, the Chinese government was content to maintain a comparatively small nuclear force. As recently as 2020, China’s arsenal was little changed from previous decades and amounted to some 220 weapons, around five to six percent of either the U.S. or Russian stockpiles of deployed and reserve warheads.

Since then, however, China has been rapidly expanding and modernizing its arsenal. In 2020, it began constructing three silo fields to house more than 300 intercontinental ballistic missiles (ICBMs). A year later, it successfully tested a hypersonic glide vehicle that traveled 21,600 miles, a test that likely demonstrated China’s ability to field weapons that can orbit the earth before striking targets, known as a “fractional orbital bombardment system.” Simultaneously, the Chinese government has accelerated its pursuit of a complete nuclear triad—encompassing land-, sea-, and air-launched nuclear weapons—including by developing new submarine- and air-launched ballistic missiles. By 2030, according to U.S. Defense Department estimates, China will probably have more than 1,000 operational nuclear warheads—a more than fourfold increase from just a decade earlier.

China’s nuclear expansion is unlikely to be a focus of U.S. President Joe Biden’s expected meeting with the Chinese leader Xi Jinping at the Asia-Pacific Economic Cooperation summit next week, but it is too important to be left entirely to defense strategists. Rather than maintaining only enough forces to be able to retaliate if attacked—China’s policy for decades—many in the United States now fear China’s nuclear buildout will give it offensive options as well. In 2021, Charles Richard, then the leader of U.S. Strategic Command, described China’s nuclear expansion as a “strategic breakout” that will provide it “with the capability to execute any plausible nuclear employment strategy.”

To understand the rationale for this transformation, some in Washington have looked to the specific nature of the buildup. For example, Secretary of the Air Force Frank Kendall has suggested that, regardless of China’s intentions, the construction of hundreds of ICBM silos amounts to developing a first-strike capability: having enough weapons to destroy an adversary’s nuclear arsenal by attacking first. But seeking to infer motivations from capabilities alone can produce misleading worst-case assumptions, especially given the tendency to project U.S. strategy onto potential adversaries, an analytical pitfall known as mirror-imaging.

In fact, China’s own nuclear strategists and experts provide a different view of Chinese thinking. Their writings and analysis since 2015 suggest that China’s nuclear expansion is less a shift in Chinese intentions than a response to what Beijing perceives as threatening changes in U.S. nuclear strategy, reflecting an acute security dilemma. Chinese analysts are worried that the United States has lowered its threshold for nuclear use—including allowing for limited first use in a Taiwan conflict—and that the U.S. military is acquiring new capabilities that could be used to destroy or significantly degrade China’s nuclear forces. Thus, many Chinese experts have concluded that China needs a more robust arsenal.

Given Chinese and U.S. fears about each other’s nuclear programs, increased communication may help to break the spiral. Based on Chinese fears, the United States should understand how changes in its nuclear capabilities and doctrine play a critical role in shaping China’s threat perceptions and perceived force requirements. Going forward, China will continue to respond to U.S. advances that are viewed as weakening China’s nuclear deterrent. Similarly, Beijing should understand that the lack of transparency regarding its rapid nuclear expansion has fueled worst-case assessments by the United States. Continued lack of transparency will lead to even greater U.S. suspicion—and feed an intensifying arms race between the two countries.

REACTIVE AGENTS

Since around 2018, Chinese experts have concluded that Washington’s nuclear posture now poses increasing challenges to China’s deterrent. In particular, they have been concerned about shifts in U.S. strategy outlined in the Pentagon’s 2018 Nuclear Posture Review. Many Chinese experts have noted that the review highlighted China as a strategic competitor and that it argued for lowering the threshold for the use of nuclear weapons, including in response to certain kinds of nonnuclear attacks. They also noted the report’s emphasis on low-yield nuclear weapons, which could possibly be used to coerce China. Citing the views of analysts such as Elbridge Colby, who served as deputy assistant secretary of defense for strategy and force development in the Trump administration, Chinese experts saw the new U.S. posture as designed, in part, to compensate for the fact that East Asia’s conventional military balance was shifting in China’s favor.

More specifically, the 2018 review increased Chinese fears that the United States might engage in limited nuclear first use during a conventional conflict with China, most likely over Taiwan. According to Chinese arms control expert Li Bin, the document suggested that “the United States would use its nuclear weapons to respond to nonnuclear Chinese aggressions.” More pointed was the analysis of Luo Xi, an expert from the Peoples Liberation Army’s (PLA) Academy of Military Science, which reports directly to the Chinese Communist Party’s Central Military Commission and helps formulate its military strategy and doctrine: “China cannot refrain from being concerned about the possibility of U.S. nuclear first use in a regional crisis,” she wrote. A retired Chinese general, Pan Zhenqiang, was even blunter: “China must contemplate a war scenario in which the U.S. may launch a nuclear attack, perhaps in a conflict over the Taiwan Strait,” he said in 2018. Another expert from the Academy of Military Science emphasized that by lowering the nuclear threshold, Washington could “promote the escalation of low-intensity conflicts to nuclear war.”

Beijing has also worried about the U.S. development of both offensive and defensive weapons systems that could negate China’s nuclear deterrent. First was the possibility that the United States was building new conventional weapons that could be used to attack China’s nuclear forces, a strategy known as conventional counterforce. In contrast to using nuclear weapons to destroy an adversary’s nuclear forces—a step that would almost guarantee nuclear retaliation—these arms allow the attacker to degrade or even destroy the adversary’s nuclear arsenal without crossing the nuclear threshold. The threat of a conventional attack on China’s arsenal is further heightened by the range of systems that might be deployed, especially long-range precision-strike weapons but also forms of cyberwarfare and electronic warfare. As one researcher from the PLA’s National Defense University noted, the United States’ growing conventional counterforce capabilities may “encourage the attacker to launch a first strike in situations where nuclear weapons are not used, undermining strategic stability.”

China fears new U.S. weapons systems will negate its nuclear deterrent.

At the same time, Chinese experts are also concerned that enhanced U.S. missile defenses could undermine China’s longtime strategy of “assured retaliation”—the ability to launch a nuclear counterattack after an enemy’s first strike. Although Chinese experts regard current U.S. missile defense as limited, their long-standing concerns about these systems intensified in the years before Beijing began building the new silo fields. To assuage China (and Russia), the United States has long justified missile defenses as aimed at threats from rogue states such as North Korea or Iran. But the U.S. Defense Department’s 2019 Missile Defense Review called for a comprehensive approach to regional missile threats, including from China, and stated that U.S. missile defense systems would be used to counter any missile attack on the United States, including presumably any Chinese counterstrike. According to Luo, the Academy of Military Sciences scholar, the United States could use missile defenses to “destroy China’s second-strike capability.”

Taken together, these two developments suggested that the United States posed an elevated threat to China’s nuclear deterrent. In essence, the United States could use conventional weapons systems (or nuclear ones) to destroy most of China’s small nuclear arsenal and then use its missile defenses to limit China’s ability to retaliate with any surviving missiles. As two PLA air force scholars wrote in 2019, this “combined use of strategic offensive and strategic defensive systems will give the United States a monopolistic strategic advantage.”

Meanwhile, Chinese concerns have been exacerbated by the collapse of the 1987 U.S.-Soviet Intermediate-Range Nuclear Forces Treaty, which had prohibited the use of ground-launched short- to intermediate-range nuclear and conventional missile systems. By removing range limits on ground-launched missiles, the treaty’s demise in 2019 led experts from China’s National University of Defense Technology to describe U.S. forward-deployed missiles as a “huge threat” to China’s mobile missiles, which they claim are vulnerable when in fixed positions during the launch phase. For this reason, an expert from the China Institutes of Contemporary International Relations warned that same year that U.S. deployment of intermediate-range missiles might cause great tension with China, perhaps even spurring an “Asian Cuban missile crisis.”

MORE WAYS TO RETALIATE

To be clear, China has not been transparent about the purpose and goals of its nuclear buildup. For example, its last defense white paper was published in 2019, before the construction of the new silo fields began. Nevertheless, indications from China differ in significant ways from the most alarmist U.S. interpretations. U.S. military leaders have argued that China’s buildup provides it with offensive options that make it far more threatening to the United States and that raise new challenges for U.S. nuclear strategy. But writings by Chinese analysts, as well as statements by Communist Party officials including Xi, suggest that the Chinese debate so far has revolved around how to better implement China’s existing strategy of assured retaliation—making sure it has sufficient nuclear forces to respond to a nuclear attack. If these indications are correct, they suggest that China’s expansion is less immediately threatening than it might appear and that a forceful U.S. response would only exacerbate unnecessary arms-race dynamics.

Consider, for instance, Xi’s remarks at the 20th National Party Congress in October 2022. During a speech, the Chinese leader called for the PLA to establish “a strong system of strategic deterrence.” The following month, the outgoing vice chair of the Central Military Commission, Xu Qiliang, noted that the PLA’s approach to strategic deterrence should be based on “asymmetric balancing”—suggesting that China would not seek nuclear parity with the United States or Russia.

Before China began building the new silo fields, Chinese strategists had also underscored the need to improve the country’s deterrent, noting that the size of its force has always been a relative figure based on what is required for a secure second strike. In 2018, for example, two arms control scholars at Tsinghua University argued that the relatively small size of China’s existing arsenal had created new opportunities for adversaries to “carry out nuclear threats.” These concerns were echoed by other Chinese experts, who argued that China’s second-strike capability was “far from assured.” Also noteworthy is what available Chinese writings omit: any discussion of moving toward a first-use strategy, even limited first use.

Many of the new capabilities China has been developing are intended to enhance survivability—the ability of its nuclear forces to withstand a first strike and be able to launch a retaliatory one. The U.S. Defense Department has acknowledged, for example, that a key purpose of China’s fractional orbital bombardment system is to evade U.S. missile defense radars, presumably for use in a potential retaliatory strike.

There have been calls in China to develop tactical nuclear weapons.

Similarly, starting in 2018, scholars affiliated with the PLA Rocket Force University of Engineering began publishing articles that examined how to better protect the land-based missiles that form the backbone of China’s deterrent. As one article described, by enhancing the country’s readiness to use nuclear weapons, silo-based forces can help “to ensure effective deterrence.” The 2020 edition of the PLA National Defense University’s Science of Military Strategy also described how combining missiles on mobile launchers, which can be widely dispersed, with silo-based missiles can give China more ways to retaliate.

Chinese experts have also discussed other ways to strengthen China’s nuclear deterrent. These include reducing reaction time—the time it would take for China’s nuclear forces to respond to an attack. Chinese strategists have debated the merits and drawbacks of a partial or complete “launch on warning” system, under which Beijing would fire its missiles after an opponent’s missiles have been launched but before impact and detonation. Another potential step includes deploying missile defenses to protect Chinese nuclear infrastructure. Chinese experts have also debated whether to contemplate strikes on systems that support the U.S. missile defense program, such as U.S. early-warning satellites—despite the potential that such a move could be highly destabilizing.

It is, of course, possible that the purpose of China’s nuclear expansion and modernization is to create a “nuclear shield” that would enable conventional offensive operations against Taiwan. In this view, by possessing a robust deterrent, China can initiate or escalate a conventional conflict against Taiwan while deterring U.S. nuclear coercion or limited nuclear strikes, thereby increasing the odds of victory for Beijing. But available Chinese sources written before the expansion began contain no direct discussion of such a goal.

There have also been calls in China to develop tactical nuclear weapons. Breaking with a past taboo, some prominent experts have publicly suggested that China may need to add tactical nuclear weapons to its arsenal to deter U.S. limited nuclear first use. If Chinese concerns about U.S. nuclear strategy continue to increase, Beijing could embrace this view, with the highly precise DF-26 theater-range missile offering a likely delivery vehicle for a lower-yield warhead. But most Chinese nuclear experts appear to oppose these weapons, and no open-source evidence has revealed any plans to field them.

SLOWING THE NEW ARMS RACE

China’s nuclear expansion has clearly been driven by its growing sense of vulnerability and insecurity in the face of evolving U.S. capabilities. But a larger and more diverse Chinese arsenal will also offer Beijing more options beyond a retaliatory strike. Suppose China develops low-yield nuclear weapons to deter U.S. limited use, for example. Chinese leaders might then have an irresistible temptation to use such weapons for coercion in a Taiwan crisis. The future trajectory of China’s nuclear strategy is uncertain, and it could shift in a more offensive direction.

Moreover, even if China’s overall strategy continues to focus on deterring a first strike instead of threatening one, several of its new systems will erode geopolitical stability. Perhaps most notably, if China adopts a launch-on-warning posture, the risks during a crisis would go up significantly. China’s limited experience operating nuclear forces that are on hair-trigger alert makes the potential for accidents or miscalculation even greater.

Although arms control breakthroughs between Washington and Beijing are highly unlikely, there are steps both could take to prevent greater escalation. For China, greater transparency about its nuclear posture and the rationale for its buildup could help alleviate some of the worst-case assumptions held by U.S. strategists. For defense strategists in Washington, understanding how the United States’s nuclear posture and missile-defense efforts shape Chinese threat perceptions may help them craft nuclear policies that Beijing would view as less provocative and hence less likely to require a response.

Unfortunately, the overall U.S.-Chinese rivalry and growing tensions over Taiwan suggest that these goals will be difficult to achieve. Indeed, China’s nuclear expansion is more likely to fuel those tensions than lead to any kind of détente. Even though Chinese leaders may view their nuclear modernization efforts as defensive, policymakers and strategists in Washington are calling for a strong response. With China very much in view, in October 2023, the bipartisan Strategic Posture Commission recommended various changes to U.S. nuclear forces, such as preparing to upload warheads currently held in reserve to existing delivery vehicles, expanding the number and types of delivery systems, and deploying more theater-range systems to the Asia Pacific. Similarly, a bipartisan expert group convened by Lawrence Livermore National Laboratory recently recommended that the United States “plan and prepare to deploy additional warheads and bombs.”

Such steps will almost certainly only strengthen China’s drive to expand its nuclear arsenal. Beijing could further increase its stockpile of nuclear weapons, deploy new delivery systems, and develop a low-yield nuclear warhead—all steps that the United States would view as threatening. Thus, the U.S. response to China’s recent plans, which are themselves heavily influenced by shifts in U.S. nuclear strategy, could speed up what has become a dangerous action-reaction cycle and potentially set off a major nuclear arms race.