On limited nuclear use in the Western Pacific

Introduction

Would China or the United States use nuclear weapons in a conflict over Taiwan? If so, what would that look like in practice? This paper examines that dark prospect. It unfolds as a series of queries designed to highlight the key factors that could influence limited nuclear use in a war in the Western Pacific.

Firm answers to these questions are not always forthcoming. The exact decision-making calculations related to nuclear employment—from both the Chinese and U.S. side—are impossible to state definitively in advance of the actual moment when such weapons might be utilized. Rather, the paper’s intent is to provide the reader insight into the issues that come into play when debating nuclear use in a Taiwan contingency. The goal is less hard answers and more a basis for further conversation.

Examining nuclear use in the Western Pacific obviously should not be conflated with endorsing it. But avoiding nuclear employment in practice might hinge, in part, on better understanding the circumstances where it could come into play in advance. At a minimum, realistic examinations of nuclear use in the Western Pacific can further raise awareness of the escalation risks in any conflict over Taiwan.

On first use

One note before proceeding: the paper allows that either China or the United States could initiate nuclear use.¹ Although China formally has maintained a No First Use (NFU) policy since it first tested an atomic bomb in the 1964, the validity of that pledge has always been a source of debate. China’s move from a minimal deterrent in the twentieth century to far more robust nuclear capabilities today has led to additional questions about the veracity of its NFU commitment.² It is assumed herein that the existence of an NFU doctrine in itself would not inhibit first use by China. For its part, the United States has never foresworn first use.

Question 1: Would a war over Taiwan remain limited?

The first question that needs to be asked about nuclear use in the Western Pacific does not necessarily concern nuclear weapons themselves. Rather it relates to the nature of any conflict over Taiwan. Namely, would it be a total war or a limited war?

A limited (conventional) war is one in which states do not apply all elements of national power to the conflict nor do they risk their existence (or at least that of the ruling regime). It differs from a total war in the sense that it is not an existential clash: even if a state loses a limited war, it will continue to exist as before and suffers less than the type of catastrophic defeat as, for example, the Axis powers experienced in World War II.

Writing on the subject almost 70 years ago, the then-academic Henry Kissinger provided a useful summation of limited war, describing it as one:

fought for specific political objectives which, by their very existence, tend to establish a relationship between the force employed and the goals to be attained. It reflects an attempt to affect the opponent’s will, not crush it, to make the conditions to be imposed seem more attractive than continued resistance, to strive for specific goals and not for complete annihilation.³

He further adds that “limited war is essentially a political act.”⁴ That is, each side must agree, tacitly, to keep the conflict limited and apply their military forces appropriately.

The United States, the Soviet Union, and China all chose this course in the Korean War, confining fighting to the peninsula itself rather than extending the conflict to each other’s homelands. For example, General Douglas MacArthur wanted to bomb Chinese bridges over the Yalu River but was ultimately denied permission by the Joint Chiefs and President Truman, who feared escalating the conflict to total war with the communist bloc.⁵

To consider a more recent case, as brutal and destructive as the Ukraine war has been, it still falls short of total war. Russia has not used its nuclear weapons nor has it deliberately struck NATO territory, even as the alliance has provided critical supplies to Ukraine. For its part, Ukraine has faced some limits on the use of Western weapons against targets on Russian territory and has hesitated, at times, to fully mobilize all of its population to fight.⁶ The United States and other NATO countries’ refusal to enter the conflict directly with their own military forces has been another important element in keeping the Ukraine war limited.

Would, then, a Taiwan conflict be a limited war (i.e., “a maritime Ukraine”) or something closer to total war? While it might seem self-evident, it’s worth emphasizing an essential factor will be whether there is a direct, large-scale clash between U.S. and Chinese military forces. If China launches an invasion attempt, does the U.S. intervene against that effort with its own air and naval forces? Alternately, does China launch a pre-emptive strike against U.S. military assets in the Western Pacific with its missile forces to preclude intervention?⁷ Each side will have a decision to make about openly engaging the other in a conventional conflict.

Even if Chinese and U.S. forces do engage in direct combat, a war might still remain limited. The Korean and Ukrainian examples illustrate that intense, destructive conflicts can be waged short of total war. In a Taiwan scenario, specific actions could be proscribed that are viewed as escalatory. For example, the U.S. might eschew direct attacks on the Chinese mainland or China could avoid targeting U.S. bases on the territory of regional allies, like Japan and the Philippines. But once Chinese and U.S. forces begin spilling each other’s blood, the ability to maintain tacit limits on the scope of a conflict—the mutual political act identified by Kissinger—will be increasingly difficult.

Several analysts have cautioned that a U.S.-Chinese fight over Taiwan would not be a short, intense battle, but rather a lengthy and grinding one.⁸ The longer such a war goes on, the more it could take on existential stakes for both Beijing and Washington. True, neither China nor the United States is likely to cease to exist as a state if it were to lose (short of mass nuclear employment), but there could be other factors that cause the U.S. and Chinese leaderships to view a potential loss through an existential lens.

From the U.S. perspective, a decisive defeat, coupled with the loss of a substantial part of its air and naval forces, might threaten the dominant position it has played in Pacific security for 80 years.⁹ That diminution in status—possibly with the attendant damage to regional alliance relationships—might rise to the level of an existential threat in the mind of a U.S. president.¹⁰

From the standpoint of the Chinese leadership, the consequences of defeat could be even more dire. It is difficult to imagine any Chinese leader failing at a Taiwan invasion attempt and surviving politically. And simply being removed from power might be the best-case scenario. His physical safety—as well as that of his immediate family—could well be in jeopardy.¹¹ A Chinese leader could therefore face a personal, existential threat in the face of defeat in addition to a national one.

For both sides, the weight of losing would also increase with accumulated casualties. China and the United States each could suffer losses in a Taiwan fight on a scale not seen since the Korean War—and do so in a relatively short time span. No one knows how leaders in Beijing and Washington will react to that level of carnage. Perhaps mass casualties would sober minds and induce an armistice, but it is equally likely (if not more so) that they would lead to escalation, as each side struggles to make its losses “count” by eventually achieving victory.

As stakes take on a more existential hue, the strain on the tacit cooperation needed to keep the war limited will become greater. Prospects for shifting to total war will increase, and with them the risk that nuclear employment could be viewed by either side as a viable option—even if it was not before the conflict began.

Question 2: Is limited nuclear use compatible with limited war?

If either China or the United States opt for a direct military confrontation, it would open the door for nuclear use as the war progressed. But once nuclear weapons are employed, can further nuclear use be controlled? Put differently, does any nuclear employment equate to total war or can nuclear weapons be used while still keeping a conflict limited?

There is, obviously, finite practical experience to work from in thinking through these questions. The only wartime employment of nuclear weapons in history—the U.S. atomic bombings of Hiroshima and Nagasaki—ended the war in which they were used. Significantly, Japan had no nuclear weapons of its own. There was never any danger of counterstrikes against U.S. cities or forces.

Cold War-era precepts offer some guidance about the feasibility of limited nuclear war, but the record is mixed at best. As scholarship by the historian Francis Gavin illustrates, one of the foremost examples of planning for controlled nuclear use—the Kennedy administration’s policy of flexible response—appears to have been less a viable strategy and more useful political rhetoric.¹² As Gavin notes, there were few substantive changes in the nation’s classified nuclear playbook—the Single Integrated Operational Plan, or SIOP—between the Kennedy administration and the preceding Eisenhower administration, which relied on the self-explanatory policy of “massive retaliation.”¹³

Little serious thought seems to have been given to limited nuclear employment—at least among the planning staffs of that era—while decision-makers appeared genuinely agnostic about the ability to control nuclear use.¹⁴ As President Kennedy’s secretary of defense, Robert S. McNamara, later testified to Congress in 1966, “It is not yet clear how theater nuclear war could actually be executed without incurring a very serious risk of escalating to general nuclear war.”¹⁵ In effect, one of the principal architects of flexible response was publicly contradicting an oft-assumed aspect of that policy: that nuclear war could reliably be waged in a limited manner.

Previous advocates of limited nuclear war also lost their appetite for the endeavor, particularly as the Soviet Union grew its own nuclear arsenal relative to that of the United States.¹⁶ After first arguing the feasibility of controlled nuclear fighting in an earlier book, Kissinger later seemed to recant in a second text:

Even with the best of intentions on both sides, a nuclear war will be more difficult to limit than a conventional one. Since no country has had any experience with the tactical use of nuclear weapons, the possibility of miscalculation is considerable… The pace of operations may outstrip the possibilities of negotiation. Both sides would be operating in the dark with no precedents to guide them and a necessarily inadequate understanding of the purposes of the opponent, if not their own. The dividing line between conventional and nuclear weapons is more familiar and therefore easier to maintain—assuming the will to do so—than any distinction within the spectrum of nuclear weapons.¹⁷

True, there were Cold War strategists who made strong cases to the opposite effect, perhaps most eloquently Bernard Brodie. He believed nuclear use could be controlled if applied correctly. His core argument was that by denying itself the option to employ tactical weapons early in a conflict (i.e., not as a last resort after conventional efforts had failed), the United States was tying its hands unnecessarily and perhaps undermining the deterrence of war in general.¹⁸

At first blush, advocates of the United States using nuclear weapons to defend Taiwan today would likely find common cause with Brodie. Yet Brodie tested his argument on tactical use against crises where the opponent either a) had only a fledgling nuclear capability (China at the time) or b) had a more robust nuclear capability but was contending with the United States over an issue not considered to be an existential threat to the opponent (the Soviets and the status of Berlin).¹⁹ Under those conditions, there was greater prospect of managing escalation and avoiding general nuclear war, in his view.²⁰

Neither of these conditions would obtain in a contemporary conflict over Taiwan. Most importantly, China has a mature nuclear force and is substantially growing its arsenal, as will be discussed. Second, the status of Taiwan appears to be a vital—even existential—issue for China in a way that Berlin never was for Moscow (at least as Brodie portrayed it).²¹ With those two important criteria removed, Brodie’s arguments for tactical use lose their currency to the contemporary situation in the Western Pacific.

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To move from the historical to the theoretical, let’s consider the general impact of one party to a conflict employing a nuclear weapon. It is possible that such action would sober the minds of all involved. One side will use a nuclear weapon, perhaps against a discrete military target, and both sides will then take a step back realizing that additional nuclear use could easily ensue and, with it, far greater catastrophe.

Here, though, there is the same problem identified earlier with respect to mass casualties in a conventional conflict: initial nuclear use could lead to a cessation of hostilities if decision-makers become sufficiently concerned about the carnage they are witnessing and the risks of further nuclear employment. But nuclear use could also lead to “doubling down”—a desire to pursue victory in order to justify the losses suffered, including those now sustained in a nuclear attack.

Furthermore, if the initiating state was sufficiently desperate to employ nuclear weapons once in an effort to turn the fortunes of the conflict, why would it not be willing to conduct additional strikes? The only reason for not doing so is either a) if its opponent yields or b) if its opponent responds with its own nuclear strike. Even in the latter case, the initiator might still employ nuclear weapons again if the fear of defeat is sufficiently great.

As indicated, initial nuclear use presents the recipient of the attack with its own dilemma: does it simply accept the attack and potentially sue for peace or does it respond with its own nuclear use, in part to show that nuclear weapons cannot be employed without reprisal in kind? The slope quickly becomes slippery, particularly if one or both parties to the war truly believe that defeat is an unacceptable outcome.

This discussion raises another philosophical question: is existential defeat by nuclear means any worse than existential defeat by conventional means? Asked here, in the quiet of peacetime, the answer may seem obvious—that defeat in a nuclear war is almost certain to be worse than defeat in a conventional war. But amidst the intensity of a direct major conflict between great powers—perhaps a prolonged one with tens of thousands of lives already lost on both sides—the answer might become muddier and restraints on nuclear use malleable in the minds of decision-makers.

The next set of questions examines more concrete questions about each side’s nuclear weapons. A useful starting point for that discussion is to examine the composition of the U.S. and Chinese arsenals.

Question 3: How do the Chinese and U.S. nuclear arsenals compare?

Generally speaking, the U.S. nuclear arsenal is larger and more diverse than China’s, but Beijing is likely to narrow that gap in the years ahead. For the moment, though, the United States still maintains a numerical advantage in active nuclear weapons, with an estimated 1,770 deployed warheads as compared to about 600 for China.²²

The United States operates a nuclear triad—that is, it has the means to deliver nuclear weapons from forces based at sea (submarines), on land (intercontinental ballistic missiles or ICBMs), and from the air (bombers). All three elements of the triad are undergoing major modernization, with the acquisition of the new Sentinel ICBM, Columbia-class nuclear ballistic missile submarine (SSBN), and B-21 stealth bomber, the latter having both a conventional and nuclear mission. The bomber should become operational in the next couple years, while the first units of the Sentinel and Columbia are scheduled to come online early in the next decade, although each program has encountered technical delays.²³

China also operates a nuclear triad, although the three “legs” are not all equally well-established. For example, China has only recently added an air component, with the fielding of a nuclear-armed, air-launched ballistic missile that can be delivered by its H-6 bombers.²⁴ At sea, China has a small force of six SSBNs, but there are important questions about their overall quality, including their acoustic quieting levels.²⁵ Perhaps to compensate for this weakness, China is deploying a new submarine-launched ballistic missile (SLBM), the JL-3, which could allow its SSBNs to strike parts of the continental United States from seas adjacent to the Chinese mainland, obviating the need for riskier long-range patrols in the Pacific.²⁶

The bulk of Chinese nuclear forces—about 80 percent—are deployed on land-based missiles.²⁷ Moreover, this percentage will only increase in the years ahead as China undertakes a major expansion of its ICBM force and, with it, grows its overall warhead count. China has already built 300 new silos and begun deploying ICBMS at some of them.²⁸ It also appears to be expanding the number of its missiles capable of carrying MIRVs, or multiple independently-targeted reentry vehicles (i.e., more than one warhead per ICBM).²⁹ Collectively, these steps could help China field 1,000 operational warheads by 2030, according to the most recent Department of Defense (DoD) estimate.³⁰

Even without those additions, China already maintains a capable land-based force anchored by solid-fueled road-mobile missiles, like the DF-31A and DF-41 ICBMs, each of which can range significant portions of the continental United States.³¹ Their mobility makes this group of missiles particularly hard to counter-target.

Question 4: Why is China expanding its nuclear arsenal?

The expansion of China’s nuclear arsenal is a significant development in its own right, but even more so when considered in light of a potential clash with the United States in the Western Pacific. How much of a relationship is there between the Chinese build-up and planning for a Taiwan contingency?

One school of thought suggests that there may not be an immediate correlation. Rather, the Chinese build-up is seen as “status driven.” That is, China sees itself as a great power—a peer to the United States and a peer (or more) to Russia. As such, it is only natural that China should have a nuclear arsenal commensurate with those two powers.³²

In some ways, the status argument follows the rationale behind China’s original acquisition of nuclear weapons as explored by scholars like Jeffrey Lewis. He argued that China’s nuclear development in the 1960s was an extension of Mao’s Great Leap Forward, an effort to expand Chinese scientific and technological capabilities on par with other leading states.³³ Notably, China quickly progressed from simple fission designs to developing and testing fusion designs—thermonuclear weapons—in part because of the prestige that level of capability conveyed.³⁴ But having achieved thermonuclear detonation, China also refrained from pursuing the massive number of nuclear weapons developed by the United States and the Soviet Union during the Cold War. By the end of that conflict, the total number of Chinese nuclear-armed missiles capable of striking the continental United States could be counted on two hands.³⁵

At that time, China’s “status” appeared to be satisfied—at least in Mao’s view and that of his immediate successors—by the technological achievement represented by nuclear weapons, unrelated to high numbers of deployed systems. Beijing may now believe quantity matters as much as quality when comparing itself to other nuclear great powers.

A second explanation for China’s build-up is more directly related to Taiwan. This could be described as the anti-coercion argument. Here, the work of the political scientist Matthew Kroenig is useful. In a comprehensive study of historical crises involving nuclear powers, Kroenig found that the state with a decisive numerical advantage in nuclear weapons usually was the victor in a given crisis. Nuclear superiority allowed the numerically dominant state to coerce the other party into accepting its desired outcome.³⁶

From this standpoint, China is pursuing its nuclear build-up explicitly to ensure rough numerical parity with the United States and thus inoculate itself against coercion in any crisis between the two, with Taiwan an obvious concern. Just five years ago, the ratio of operational Chinese nuclear weapons to that of the United States was roughly 1:6 in the U.S.’s favor.³⁷ In the past few years, China has improved that ratio to about 1:3 and could reach a roughly 2:3 ratio by the end of the decade if current Department of Defense projections are correct. Previous DoD estimates have suggested the Chinese inventory could grow to 1,500 operational warheads by 2035, giving it near a 1:1 equivalency with the U.S. arsenal by the middle of the next decade.³⁸

To some extent, the exact motive for the Chinese nuclear build-up may matter less than the reality of the capabilities it bestows upon Beijing. Whether driven by matters of great-power status or because it understands the coercive math explicated in Kroenig’s work, the result is the same: China has a much-expanded nuclear inventory, one whose size would significantly complicate the United States’ response in any crisis over Taiwan.

This discussion also highlights the interactive nature of nuclear force-sizing among the great powers. Either a prestige-based explanation or an anti-coercion one rests on China viewing its nuclear capabilities in contrast to those of the United States (and possibly Russia’s as well). It is important to recognize that great powers size their military capabilities—perhaps especially so their nuclear arsenals—in relation to one another.

Question 5: What tactical nuclear weapons do China and the United States have?

Both the Chinese and U.S. nuclear arsenals are currently dominated by strategic systems. China does not appear to have any tactical weapons, while the United States’ tactical options are limited.

By way of background, tactical weapons are intended to achieve some localized impact, often related to battlefield conditions.³⁹ In contrast, strategic systems are intended to have much broader effects, such as deterrence, war termination, or, in extremis, retaliation for an opponent’s strategic nuclear use.

Given their different purposes, tactical and strategic weapons feature contrasting levels of explosive yield. Tactical weapons have far less output, in some cases as low as a single kiloton or less. A universally accepted upper limit for the yield of tactical weapons is elusive, with 20 kilotons or 50 kilotons sometimes suggested as informal ceilings for considering a weapon “tactical.” The broader point to understand is that the yield of strategic systems is far greater than tactical weapons, with some strategic warheads in the arsenals of major nuclear powers exceeding 400 kilotons and even surpassing one megaton.⁴⁰ (Note: One kiloton equals the explosive power of 1,000 tons of TNT; a megaton is 1,000 kilotons.)

But these categories can be somewhat nebulous and are context-dependent.⁴¹ For example, the “Little Boy” bomb detonated over Hiroshima had an explosive yield of 15 kilotons, which, by contemporary standards, would label it a tactical weapon.⁴² But it contributed strategic effects in terms of eventual war termination. The bomb also killed at least 70,000 Japanese with its initial blast.⁴³ This illustrates another important point: even tactical weapons can cause significant loss of life if detonated over densely populated areas.

China’s lack of tactical options is perhaps unsurprising given China’s small nuclear arsenal during the Cold War, the era when tactical weapons were arguably at the peak of their prominence. Both the Soviet Union and United States fielded thousands of these weapons and each had their own doctrine and theories for using tactical weapons as warfighting elements.⁴⁴ After the Cold War’s end, the United States significantly reduced its stocks of tactical weapons and withdrew almost all of them from active deployment under President George H.W. Bush.⁴⁵

Today, the United States has just three types of operational tactical nuclear weapons. The first of these is the B61 gravity bomb. The term “gravity bomb” simply connotes that this is a free-fall weapon: the delivery aircraft must fly over the target and drop the B61 like an old-fashioned World War II bomber. There are different variations of the B61; those currently in service are “dial-a-yield” bombs.⁴⁶ That means these weapons can be programmed to produce varying levels of explosive output, possibly as high as 150 kilotons, as low as less than a kiloton, or various yields in between.⁴⁷ The B61s can therefore be operated in either tactical or strategic mode.

The Air Force’s land-based version of the F-35 (the A variant) has been certified by the Department of Energy (DOE) to deliver the B61 and that fighter’s stealth characteristics could help it perform the nuclear delivery mission better than its non-stealthy predecessors like the F-16 or F-15.⁴⁸ The B61 could also be delivered by a long-range bomber like the stealthy B-2 or its incoming replacement, the B-21.⁴⁹ But stealth, while an important advantage, is not an absolute guarantee of survivability. This underscores the central drawback of the B61: the requirement to directly overfly the target—as opposed to firing a standoff weapon at a distance—exposes the delivery aircraft to a higher degree of threat from opposing air defenses.

The United States’ second main tactical option is the W76-2 warhead. It is derived from a thermonuclear warhead (the W76-1) carried by the Navy’s Trident submarine-launched ballistic missile.⁵⁰ In the W76-1, a small nuclear fission explosion triggers a larger fusion reaction, producing a thermonuclear detonation. In the case of the W76-2, only the initial fission trigger is retained, producing a much lower warhead yield, estimated by open sources at eight kilotons.⁵¹

The W76-2 tactical warhead is also delivered by the Trident SLBM, a strategic delivery vehicle.⁵² It has been suggested that its launch might confuse China (or even Russia) about the payload of a missile being fired from a U.S. SSBN: is the Trident carrying a single tactical warhead or its usual payload of multiple strategic warheads? Could such a launch scare an opponent into launching its own strategic warheads before the W76-2 arrives on target? This discussion again enters the realm of the hypothetical, but “launch ambiguity” is still a concern worth at least noting with respect to the W76-2.⁵³

In theory, the United States has a third tactical option, another dial-a-yield warhead, the W80, carried by the U.S. Air Force’s AGM-86 air-launched cruise missile.⁵⁴ But this is an aging duo, with both the missile and warhead nearing the end of their service lives. Designed in the 1970s, the AGM-86 missile lacks stealth characteristics and flies at subsonic speeds; its ability to survive contemporary Chinese air defenses is highly questionable.⁵⁵ The DOE is working on a refurbishment of the W80, designated the W80-4, that can be delivered by the Air Force’s next-generation, stealth cruise missile.⁵⁶ But that missile-warhead combination will not be available until 2030, at the very earliest.⁵⁷

Congress also continues to fund development of a fourth tactical option, a nuclear-armed submarine-launched cruise missile (SLCM) for the Navy’s fleet of attack submarines.⁵⁸ However, one senior Navy official has suggested meeting the intended goal for an initial operating capability—by 2034—could be challenging.⁵⁹

Question 6: How would tactical nuclear weapons affect a Taiwan conflict?

For at least the next five years, the only two viable U.S. tactical options are likely to be the B61 gravity bomb and Trident delivery of the W76-2 warhead. Meanwhile, China still has no tactical nuclear weapons. This leads to a surprising question: is that a good thing or a bad thing when contemplating a Taiwan conflict?

One line of argument holds that tactical weapons can serve as a break on total war, to include general nuclear war. They carry the gravitas of nuclear use but generally have much more limited physical effects, especially if employed against military targets as opposed to population centers. Tactical use could therefore make it easier for an opponent to back down as opposed to if more powerful nuclear weapons had been directed against it. Alternately, tactical weapons could present more measured options for responding to an opponent’s nuclear first use—a way to signal resolve against nuclear employment without resort to larger, strategic weapons.

Viewed in this light, tactical weapons provide a necessary interim rung on the escalation ladder, one where both sides can step off before widespread use of more powerful nuclear weapons comes into play. To return to Kissinger’s original formulation, tactical weapons hold the prospect of extending the tacit political cooperation necessary for limited war into the nuclear realm.

But there are problems with this argument. Precisely because they are less destructive than strategic systems, tactical weapons might make crossing the nuclear threshold easier. Once these weapons are introduced to a conflict, however, there is simply no assurance that further nuclear employment would remain at the tactical level. In that regard, do tactical weapons ultimately make strategic use more likely by introducing nuclear weapons into the conflict in the first place?

This is the central dilemma of tactical weapons: whatever merits they theoretically have in controlling nuclear war, they substantially lower the nuclear threshold with no promises regarding follow-on use. Needless to say, there are no binding rules: because one side opens with a five-kiloton bomb, the other side is under no obligation to respond in kind. An opponent can immediately escalate to strategic use if it sees advantage in doing so. Indeed, this might be the case if the United States employed a tactical weapon in the Western Pacific, as China only has strategic systems with which to respond at this time.

It is possible to make two other suppositions about how tactical options could affect employment decisions in the Western Pacific. The first is that the United States might be more willing to initiate nuclear use, as it has tactical options whereas China does not. Indeed, within the U.S. think tank community, there is a burgeoning discussion about the United States planning to use tactical weapons to defend Taiwan from the outset of a conflict with China.⁶⁰ To be clear, this is not an official U.S. position, but its consideration in the public policy realm illustrates how the existence of tactical options can lead to more forward-leaning positions on nuclear use.

The second supposition is that China would be less likely to instigate nuclear use because it lacks tactical options. But caveats are also needed here. One of the underlying assumptions of this paper is that nuclear use is most likely in a conflict when one side seeks to avoid existential defeat. As stated, in the Chinese case, the risk might not just be to national standing but to a leader’s physical survival if a Taiwan invasion attempt failed. Any leader desperate enough to use nuclear weapons under those circumstances might not get bogged down in the details of kiloton output.

Having tactical weapons thus could make nuclear employment more attractive, but not having these weapons does not, by any means, preclude nuclear use. This discussion also underscores that a Chinese leader might ultimately have a more compelling reason to use nuclear weapons whereas a U.S. leader might currently have better options (or at least more diversified choices) for actual nuclear employment.

An essential factor to watch is whether China pursues its own tactical weapons at some point.⁶¹ Both the Department of Defense and independent experts have argued this is likely, if not inevitable.⁶² Timelines for deployment of such a capability are uncertain. A purpose-built, low-yield weapon could require new designs and, possibly, nuclear testing to confirm their efficacy.⁶³ Analysts at the Bulletin of the Atomic Scientist have speculated about a more direct option: China could “switch off” the secondary physics package in one of its thermonuclear weapons, reverting the warhead to the lower yield of its fission trigger.⁶⁴ (This would be similar to what the United States did in creating the W76-2 tactical weapon from the original W76-1 thermonuclear warhead, as discussed above.)

A Chinese decision to pursue tactical options would likely signal an important shift in mindset regarding the usability of nuclear weapons.⁶⁵ Once in hand, tactical options might encourage Chinese defense planners to more carefully consider their practical applications in the same way some U.S. strategists are now publicly discussing tactical use in a Taiwan conflict.

This highlights another problematic aspect of tactical weapons: they move the nuclear threshold from one of strategic desperation (i.e., avoiding existential defeat well into a war) closer to the realm of operational utility (i.e., achieving specific battlefield effects early in a conflict). For that reason, the risk of nuclear use would seem to increase exponentially if both sides have tactical options in a future clash between China and the United States in the Western Pacific. All of that said, it is important to emphasize that China has so far taken no substantive steps to develop tactical nuclear weapons, at least as can be discerned from open sources.

This presents another difficult question: does U.S. possession of tactical options—and the development of new ones—incentivize China to seek its own low-yield options? Recall the interactive nature of nuclear planning among the great powers, as touched on above. It is a point worth considering if Chinese tactical capabilities are something the U.S. would prefer not to see. Confounding matters, though, is that U.S. nuclear planning is also influenced, in turn, by Russian capabilities. That country’s large inventory of tactical warheads is a separate factor that drives U.S. interest in this class of weaponry.⁶⁶

A closing thought involves operational effectiveness. For almost 25 years, thinking on tactical nuclear use within the U.S. defense planning community largely went fallow following President Bush’s decision to pull most U.S. tactical weapons from the field in 1991.⁶⁷ Russia’s 2014 invasion of Crimea and subsequent concerns over NATO’s ability to defend the Baltic states revived discussions on the utility of tactical nuclear weapons. Playing a central role in those debates was a series of wargames conducted by RAND that examined tactical use in a Baltic scenario.⁶⁸

One excursion was telling: the team playing NATO employed low-yield weapons against Russian forces in Latvia. The Russian response was to strike multiple rear-area NATO airbases with 50-kiloton warheads, targeting a significant portion of the alliance’s air assets including its stealth fighters. In short, after the alliance opened the door to nuclear use on the battlefield, Russia employed its own follow-on strike for much greater effect.⁶⁹ This raises another essential consideration in a Taiwan contingency: which side would gain more operational benefits once the nuclear threshold is crossed?

Question 7: Would China or the United States benefit more from limited nuclear employment?

Given its history with Cold War tactical nuclear weapons and current monopoly on these systems (at least within the U.S.-China dynamic), it is tempting to suggest the United States is better positioned to use nuclear weapons in a conflict over Taiwan. China has a far less developed body of public writings on nuclear warfighting, certainly as compared to the United States.⁷⁰ Mitigating against this, though, is an important factor: geography. The United States only has a finite number of places it can employ nuclear weapons in a war with China—namely, against Chinese ground forces fighting on Taiwan, against Chinese naval forces at sea, and against military installations on Chinese territory itself.

In the first instance, the obvious consideration is potential collateral damage to Taiwan’s population and infrastructure if the United States directed tactical strikes against a Chinese invasion force once ashore. The main island of Taiwan is about 14,000 square miles—not necessarily small but also not massive. Yet it supports a population of nearly 24 million, giving it a population density of roughly 1,700 people per square mile.⁷¹ There may be a very limited number of places where the United States could use a tactical nuclear weapon to good military effect and avoid close proximity to Taiwanese population centers. Likewise, how would a tactical strike affect local Taiwanese military units opposing the Chinese invasion force?⁷²

Given the challenges of nuclear use on Taiwan itself, some U.S. analysts have posited targeting the Chinese invasion fleet at sea with tactical strikes.⁷³ However, to a surprising extent, the destructive power of nuclear weapons dissipates over water, leading to a limited area in which a blast is lethal to a ship.⁷⁴ Writing in the middle of the Cold War, one U.S. Navy weapon effects specialist was candid about the utility of nuclear weapons at sea:

Survivability when faced with a nuclear weapon is probably better, however, than many naval officers have been led to believe. In the general scenario which might be proposed for the next war at sea, the nuclear weapons will most likely be directed against the task force or, at least, against the major ships. The ships within about a thousand yards of a modest burst, about 10 kilotons, will not survive. However, a one-megaton nuclear airburst is fully survivable as close as 5,000 yards.⁷⁵

The tactical weapons in the U.S. arsenal today have far smaller yields than the megaton blast referenced. In the case of the more modest 10-kiloton detonation (comparable to the estimated eight-kiloton yield of the W76-2 warhead), the effective lethal radius is only a little over a half mile (i.e., a thousand yards). As long as an opposing naval force—such as a Chinese invasion fleet—remains reasonably dispersed, it becomes difficult to eliminate multiple vessels with a single tactical strike.⁷⁶ Instead, nuclear use might only sink a single ship at a time or, at best, a handful of vessels. In other words, nuclear weapons can be used to kill ships, but they are not terribly efficient at doing so.

To compensate, some U.S. strategists have suggested that the Chinese armada could be targeted at the end of its journey, when it would need to assemble in close formation to either dock at Taiwanese ports or disburse amphibious forces against the beaches.⁷⁷ But this raises additional questions. In his seminal study of Taiwanese invasion scenarios, Ian Easton identified 14 potential beaches where China could move forces ashore.⁷⁸ Would each of these zones require an offshore tactical strike? Would repeated attacks be needed on each area? Scenarios can be drawn where U.S. tactical use is not truly limited but rises to a dozen or more strikes at least.

Viewed in a vacuum, the United States’ third option for nuclear employment is the most advantageous: strikes against military installations on the Chinese mainland. The possible target list here is almost endless, to include airbases, ports, missile sites, radar sites, and assembly zones for invasion troops. There is no denying the pure military logic of striking such facilities nor that nuclear weapons could attack those targets with devastating efficiency. The essential issue, of course, is that such strikes would not take place “in a vacuum.” Nuclear strikes on Chinese territory—even to achieve tactical or operational effects—could carry immediate strategic consequences.

In contrast to the U.S. position, China has a broader array of potential targets set against the expanse of the Pacific. These would include nuclear use against U.S. ships, U.S. forces on the territory of regional allies, U.S. territories like Guam, non-contiguous states (Hawaii and Alaska), and facilities on the West Coast or, conceivably, throughout the continental United States. As with U.S. strikes against the Chinese mainland, some or all of these target sets could prompt a strategic response. But viewed exclusively through the narrow lens of military utility, nuclear use would seem to have at least three potential advantages for China.

First, it would allow China to devastate important U.S. logistical nodes in the First Island Chain. Just as the U.S. would look at the Chinese coast and see abundant targets, so, too, would China in surveying U.S. military bases in Japan and the Philippines, to include airfields, ports, munitions depots, radar installations, and a host of other critical installations. China already possesses ample means to strike these facilities with conventionally armed ballistic and cruise missiles.⁷⁹ But nuclear use could achieve results with greater economy and more permanence than damage from conventional strikes, which could be repaired more quickly.

Second, nuclear use could augment and simplify China’s ability to strike out to the Second Island Chain. Here, again, China already has the means to target U.S. military installations in the Second Island Chain, notably those in Guam, with conventionally armed ballistic and cruise missiles.⁸⁰ But maintaining pressure on U.S. military facilities on Guam—at a distance of over 1,800 miles from the Chinese coast—could be taxing and extremely resource-intensive with conventional weapons.⁸¹ A single nuclear weapon could cripple U.S. operations on Guam in one stroke.

Third, and perhaps most importantly, nuclear weapons could extend Chinese reach against U.S. bases and logistics in the Central and Eastern Pacific. Most of China’s conventional missile options are limited by range to targets in the First and Second Island Chain.⁸² Meanwhile, China’s navy, while large and powerful, lacks the logistical capabilities and basing network to conduct large-scale operations across the breadth of the Pacific.⁸³ As a result, U.S. military installations in Alaska, Hawaii, and on the West Coast are under far less threat from Chinese conventional strikes than U.S. facilities in the Western Pacific.

True, this is not an absolute sanctuary. China has nuclear-powered submarines that conceivably could attempt clandestine cruise missile strikes outside the Western Pacific.⁸⁴ China is also developing a conventionally armed, intermediate-range ballistic missile, the DF-27, that could hold Alaska and Hawaii at risk.⁸⁵ Relatively speaking, though, U.S. bases in the Central and Eastern Pacific do not face nearly the same level of threat as their counterparts in the Western Pacific. Nuclear use could change that.

This discussion of possible uses for nuclear weapons is far from comprehensive.⁸⁶ At a minimum, though, nuclear weapons would allow each side to strike targets in the Western Pacific more economically and with far greater force than is allowed by conventional options. But in China’s case, the addition of nuclear weapons would also add target sets it has limited conventional means to strike, namely, U.S. rear-area bases in the Central and Eastern Pacific. This is not to definitively say that nuclear use would benefit China more, but it is to caution that the answer is not clear cut.

As noted, the preceding discussion elides the question of escalation and retaliation to focus on matters of military utility. Moving from the theoretical to the real world, the reaction of the party attacked with a nuclear weapon would obviously need to be factored into the equation. The nature of that response could impact the net value of any nuclear strikes if the initiating party was dealt a more devastating blow in reply. This returns the discussion to whether nuclear use can be controlled once initiated, a question which hinges on mutual understanding of each side’s red lines.

Question 8: Do China and the United States understand each other’s nuclear red lines?

As stated earlier, at the core of limited war is the notion of tacit cooperation: each party must avoid those actions it believes could push its opponent to total war. In order to maintain that cooperation, there needs to be a clear understanding of what an opponent finds unacceptable—not just unwanted or painful—but truly intolerable. In layman’s terms, these are “red lines,” the limits of pain or intrusion that one party to a conflict cannot accept.

Because of the power of nuclear weapons, establishing and understanding red lines for limited employment would be extremely difficult.⁸⁷ How does one determine beforehand what nuclear use an opponent might accept—or at least find sufficiently acceptable that it only replies with its own limited nuclear strike? Is “acceptable nuclear use” even a viable concept or, instead, the ultimate oxymoron?

Further complicating matters is the opaqueness of views on nuclear employment among the senior Chinese leadership. This is something of a “black box” even as it would be an essential variable in estimating the ability to keep a nuclear war in the Western Pacific limited.

For example, would the Chinese leadership truly be more accepting of nuclear strikes against amphibious forces at sea as opposed to strikes against bases on Chinese territory? Even though such an option might avoid direct use against the Chinese homeland, attacks against landing forces at sea could still kill tens of thousands of Chinese troops and confront a Chinese leader with the prospect of an existential defeat. Consider that in the 1980s, the Reagan administration essentially asserted that the Soviets could not use nuclear weapons against U.S. carrier battlegroups without expecting retaliation in kind on land (i.e., nuclear war started at sea would not remain so).⁸⁸ Alternately, if one moves away from scenarios for use at sea, is there potentially any use of nuclear weapons against Chinese territory that would not elicit a nuclear response?

In order to provide insight into possible Chinese reactions, some U.S. think tanks have staged wargames simulating nuclear use in a Taiwan conflict.⁸⁹ Presumably, similar games have been undertaken within the U.S. government. Important as these exercises are, they ultimately require U.S. players to stand in for Chinese decisionmakers.⁹⁰ Even the most insightful Sinologist is still only guessing at Chinese intentions and reactions. The result is simply an impression of possible Chinese red lines rather than clearly established boundaries against which to weigh U.S. actions. Modeling Chinese responses is not unhelpful, but it is still ultimately conjecture.⁹¹

From the U.S. side, there may also be a lack of clarity regarding its nuclear red lines. As noted, China has an array of potential targets in the Pacific in terms of the types of U.S. territory it could strike. It is tempting to impose an artificial hierarchy on them vis-à-vis the U.S. response: for example, that striking Guam might not be as provocative as an attack on Hawaii, which itself might be viewed as a lesser violation than nuclear use against Los Angeles or another West Coast city. But this is another supposition, one that may not hold up in practice. Would a U.S. leader necessarily be more accepting of a nuclear strike against Guam, a U.S. territory, as opposed to a non-contiguous U.S. state or mainland city? There is no set answer here and the precise response could be idiosyncratic to a given president.

Under the U.S. system, the potential reaction to specific types of nuclear employment could thus change from administration to administration. Depending on a president’s personal views, this could include responding in kind to any nuclear employment against U.S. personnel or territory regardless of location (i.e., Guam might count as much as Los Angeles after all). The broader point to emphasize is that if U.S. citizens cannot reliably predict how their own government might respond to specific types of nuclear use, it is asking much of the Chinese leadership to have perfect clarity on the subject. When it comes to nuclear red lines, Beijing will be guessing as much as Washington.

It is therefore hard to be optimistic about keeping nuclear use limited in a war over Taiwan. Controlled nuclear use would seem to require certainty about reaction—that limited employment of a nuclear weapon will not precipitate a strategic response from an opponent. Red lines could provide that certainty if they are clearly understood and adhered to. If they are not understood or observed, then it becomes difficult to reliably predict outcomes. Without certainty regarding response, any nuclear use against another nuclear power becomes an open-ended gamble.

Before concluding this discussion of nuclear use in the Western Pacific, two other practical factors need to be weighed: the potential impact of active missile defenses and the reactions of U.S. Pacific allies. These are examined in the final two questions.

Question 9: How would missile defenses impact nuclear use?

After years of debate regarding their capabilities under combat conditions, active missile defenses appear to have performed well in extended use in Ukraine and, to a lesser extent, in blunting Iranian ballistic missile attacks against Israel.⁹² How useful would U.S. active systems like Patriot, the Terminal High Altitude Area Defense (THAAD) system, and the Navy’s Aegis radar/Standard Missile combination be in defending against nuclear-armed missiles? The United States is also investing heavily in a ground-based missile defense system for Guam.⁹³

Collectively, active defenses could offer important protection to U.S. forces and bases against a nuclear strike in the Western Pacific. But at least three caveats need to be added to that assertion. First, even the best active defenses are still not foolproof, an essential consideration if the incoming payload is nuclear. Second, the volume of missile launches seen in Ukraine and Israel might pale in comparison to that in a full-blown war with China.⁹⁴ It would be wrong to automatically assume the exact same performance of U.S. active defenses under substantially higher rates of enemy fire.

Finally, U.S. theater defense systems are likely to be at their most effective early in a conflict over Taiwan when the inventory of U.S. interceptors is highest. Few analysts expect China to lead with a nuclear strike. Instead, Chinese nuclear use is likeliest further into a war when the U.S. interceptor stockpile will be at its lowest. This could result in U.S. active defenses being husbanded to protect certain locations leaving others necessarily exposed. For example, civilian population centers could be favored over military facilities as interceptor stockpiles are drawn down. There is at least some prospect of the U.S. exhausting its interceptor supply entirely if a war with China went on long enough.⁹⁵

In conducting a limited nuclear strike, China could also use a missile of greater range and speed—one which theater defense systems were not designed to address. For example, China could employ an ICBM to attack a comparatively close target like Guam. Russia has already hinted at this tactic with the use of its experimental Oreshnik missile in Ukraine.⁹⁶ The point is that while U.S. active defenses might complicate Chinese calculations about how to employ nuclear weapons, they are unlikely to prevent said use altogether.

A final but important point regards strategic defenses. China has no means of defending its homeland against long-range attack by U.S. intercontinental ballistic missiles or submarine-launched ballistic missiles. For its part, the United States does have a capability against ICBMs—the Ground-based Midcourse Defense (GMD) system—but there are important questions about its effectiveness.⁹⁷

Broadly speaking, defeating a ballistic missile becomes proportionally more difficult as its range and speed increases. The successes seen against short- and intermediate-range missiles in Ukraine and Israel may not translate to much longer-range threats, like ICBMs, which travel at far greater speeds.

The GMD system also consists of just 44 interceptors deployed at two bases in Alaska and California.⁹⁸ Further, it would not be surprising if the intent was to launch at least two and possibly as many as four interceptors at a given warhead to ensure the best possible chance of destroying it. Depending on how they are allotted, back-of-the-envelope calculations suggest GMD is capable of handling between 11 to 22 warheads, assuming the system works as intended—of which there remains no guarantee.⁹⁹ This level of protection would be of marginal value if a war over Taiwan escalated to a full-scale strategic exchange between China and the United States.

Could GMD have some utility against limited Chinese nuclear strikes in the Central or Eastern Pacific? Possibly, but given that the system has a mixed record under controlled test conditions and, of course, has never been tested against a real-world threat, it would seem dangerous to depend on GMD. There are also broader questions that can be asked about decoys and other means China could employ to deliberately spoof the system. At best, GMD might represent a chancy, last-ditch effort to stop a limited, long-range nuclear strike. This should not be confused with a proven, assured means of countering Chinese nuclear use.

To summarize, one can rightly laud the impressive technological achievement of U.S. theater-level defenses but still maintain perspective on their potential role in a Pacific conflict. Their past performance is no guarantee of similar proficiency under the intense conditions of a full-scale war with China. And when applied to countering nuclear use, there is a real risk of misplaced confidence, particularly against longer-range missiles. Finally, there will be critical concerns about ordnance stocks as the war goes on and interceptors are rapidly expended.

Question 10: How would U.S. Pacific allies react to nuclear use?

Access to bases on the territory of its Asian allies would be critical to enabling U.S. military operations if it chose to fight China directly over Taiwan.¹⁰⁰ In particular, facilities in Japan and the Philippines would likely be essential, as they bracket Taiwan in the First Island Chain. Australia could also conceivably provide useful strategic depth if U.S. and allied military facilities in the First and Second Island Chains were seriously degraded.¹⁰¹ The U.S. also has important military facilities in South Korea, although that country’s willingness to make them available for a Taiwan contingency is more doubtful.¹⁰²

Indeed, it is not certain that any of the four primary U.S. Pacific allies—or even some of them—would openly support the United States in a war against Taiwan, at least one in which they themselves had not been attacked first by China.¹⁰³ Nuclear use—or even the prospect of nuclear use—could weaken this tenuous support further.

Estimating the regional response to nuclear employment is complicated by the piecemeal nature of the U.S. alliance system in the Pacific. For better or worse, the North Atlantic Alliance has kept nuclear issues at the forefront of European defense planning decades after the Cold War’s end. Within NATO, the Nuclear Planning Group provides an institutional mechanism for discussion of U.S. (and British) nuclear capabilities and planning as they relate to the alliance’s defense.¹⁰⁴ The U.S. can engage all its European allies collectively on nuclear matters.

The dynamics of U.S. alliances in the Pacific are fundamentally different, as those relationships are all based on separate bilateral agreements not a multilateral structure with a standing organization for discussing nuclear matters. There is also far less history of consultation to build on; there never was an Asian equivalent to NATO’s dual-key arrangements during the Cold War with respect to potential U.S. nuclear use in the Pacific theater.¹⁰⁵ Asia is therefore more of a “blank slate” when it comes to allied perspectives on nuclear use.

For the purpose of discussion, it is still possible to identify two general responses.¹⁰⁶ The first is that a given ally summarily rescinds its support to the United States. That is, if either China or the United States initiates nuclear use, the ally bars further access to its territory for U.S. forces and withdraws any military units of its own from the fight. Such a response could be another factor weighing against the United States initiating tactical nuclear use if, for example, it meant loss of access to vital bases in Japan or the Philippines. At a minimum, allied reaction and the concomitant impact on the U.S. logistical network would need to be weighed carefully against the operational value of any nuclear strikes.

Along these lines, China could consider ways to calibrate its own nuclear use (or threatened use) to force a U.S. ally out of the fight, undercutting U.S. logistics. The danger for Beijing is that nuclear employment or threats could also have the opposite effect—pushing an ally closer to Washington rather than driving a wedge between them. China is not above overplaying its hand.

That leads to the second possible reaction to nuclear use: the U.S. ally remains in the fight, accepting the attendant risks. At that point, the ally might look at the ongoing struggle between China and the United States and realize that it, too, has an existential stake in the conflict’s outcome. A decisive loss by the United States would deprive the ally of its longstanding protector and leave it to face a victorious and possibly vengeful China. If Washington contemplated nuclear use out of fear of losing decisively, an ally might share that concern and support nuclear employment.

There is no certainty here. Pacific allies could serve as a restraint on U.S. nuclear employment, possibly working in favor of keeping a war over Taiwan limited. But there are also excursions where their own security concerns encourage nuclear use. Whether China has already targeted an ally’s territory with conventional force, the level of casualties incurred by an ally’s military and civilian population, and which side (China or the U.S.) first crosses the nuclear threshold are all factors that could shape an ally’s response.

Summary thoughts

Discussing potential nuclear use in the Western Pacific is not an easy conversation to have, but it is a necessary one, arguably as important as any in international security today. Understanding the nuclear danger in a war over Taiwan does not automatically obviate it, but it is still the first step toward guarding against the worst possible outcome. Responses, rejoinders, and other reactions are therefore encouraged to the ideas and questions set out above. In addition, the following four related thoughts are offered for additional consideration.

First, it is tempting to dismiss U.S. strategists proposing nuclear use in a Taiwan conflict as reactionary or reckless. But an argument can also be made that these analysts are actually viewing a potential war in the Western Pacific with clear eyes. Just four or five years ago, it was still novel to discuss a conflict over Taiwan going nuclear in public debates. That the prospect is now accepted as almost de rigueur is not entirely a negative. It reflects recognition of how brutal a conventional fight might be for both sides and how this could lead either China or the United States to contemplate nuclear employment.

This is not intended as an endorsement of nuclear use by any means. It is simply to observe that it is sadly correct (even essential) to include that possibility in any reasonable discussion of a war over Taiwan. But if one introduces the notion of nuclear use, it is also incumbent on the discussant to examine the full consequences of that action. Where could limited nuclear use lead? That question also needs to be asked with respect to the critical matter of whether the United States should commit its forces to defend Taiwan in the first place.

Second, the essential incubator for a nuclear war in the Western Pacific remains a conventional one. Each side must carefully consider that reality before choosing to engage the other’s military forces. Washington will face an important decision, as touched on, but Beijing will also bear unique responsibility in this regard. Writing from the U.S. perspective, it is tempting to see U.S. choices and actions as the only variable in the equation regarding nuclear use. Yet if there is no invasion attempt, there is no real prospect for a conventional war between China and the United States, and no ensuing danger of limited nuclear use or worse.

Compounding matters further would be if China opted for a no-warning conventional strike against U.S. bases in the Western Pacific concurrent to moving against Taiwan. That could impel the United States into a war whether it wanted one or not—and with much-reduced conventional forces to fight it. The nuclear risk in the Western Pacific is a shared danger and it is incumbent on China to mitigate it as much as it is on the United States.

The United States, in turn, could have unique responsibilities with respect to nuclear planning. This leads to a third point: U.S. policy statements and weapons programs do not exist in a vacuum. What is said and discussed publicly—in addition to the nuclear weapons that are in hand and being developed—can impact how China responds with the sizing and structure of its own nuclear forces. China’s current nuclear build-up is likely a product of that silent dynamic. In considering the critical issue of tactical weapons—and China’s forbearance of these capabilities to date—it is worth asking if there are ways to mitigate any incentive for China to match U.S. low-yield capabilities. There may not be, but given the immense consequences of China fielding tactical nuclear weapons, it is a matter worth serious consideration from the U.S. side.

Finally, the reader will have noticed that no hard definition of limited nuclear use was ever offered in this text. That’s because there is none. The best approximation is that “limited use” is simply not a full-scale nuclear war. Beyond that, there are no firm parameters regarding number of warheads, yields, or target selection that definitively constitute limited use. The concept exists largely in the eye of the beholder. Indeed, in the moment of action, limited use will simply be what the initiating nuclear power hopes its opponent considers to be so.

By its very nature, then, limited nuclear use is dependent on the interaction between the highly subjective perceptions of two very different actors. One quickly understands the challenge in trying to regulate such an activity. The most striking thing in this paper is the persistence of ambiguity and uncertainty: so many questions that cannot be answered. There are too many unpredictable variables to accurately model in advance how limited nuclear use might play out in practice in the Western Pacific.

Perhaps the most important question of all remains: if limited nuclear use cannot be reliably controlled, should it be hazarded in the first place? Neither China nor the United States would initiate a limited strike in the belief that it is starting a full-scale nuclear war. But under the unprecedented emotional and psychological strain of the first two-sided nuclear war in history, how will leaders be able to judge the consequences of first employment? Moreover, if the tacit cooperation required to keep a conventional war limited had already broken down, what prospect is there of the careful mutual restraint needed to moderate a nuclear exchange? These are only hypothetical questions for the moment yet ones which could conceivably be tested in practice in the coming years.

Endnotes

1
For further analysis of motivation for nuclear use by both China and the United States, see Mike Sweeney, “Why a Taiwan Conflict Could Go Nuclear,” Defense Priorities, March 2021, https://www.defensepriorities.org/explainers/why-a-taiwan-conflict-could-go-nuclear/.
2
See Christopher P. Twomey, “China’s Nuclear Doctrine and Deterrence Concept,” in China’s Strategic Arsenal: Worldview, Doctrine, and Systems, eds. James M. Smith and Paul J. Bolt (Washington, DC: Georgetown University Press, 2021) 45–62. For one of the first analyses to explicitly examine the impact of a potential Taiwan conflict on China’s NFU policy, see also Baohiu Zhang, “The Taiwan Strait and the Future of China’s No-First-Use Nuclear Policy,” Comparative Strategy, vol. 27, no. 2 (2008) 164–182, https://doi.org/10.1080/01495930801944701. For more recent developments on China’s NFU policy, see also Sari Arho Havrén, “China’s No First Use of Nuclear Weapons Policy: Change or False Alarm?” Royal United Services Institute, October 13, 2023, https://www.rusi.org/explore-our-research/publications/commentary/chinas-no-first-use-nuclear-weapons-policy-change-or-false-alarm.
3
Henry A. Kissinger, Nuclear Weapons and Foreign Policy (New York: Council on Foreign Relations, 1957) 140.
4
Kissinger, Nuclear Weapons and Foreign Policy, 140.
5
See H.W. Brands, The General vs. The President: MacArthur and Truman at the Brink of Nuclear War (New York: Doubleday, 2016) 359–371. See also, “The Joint Chiefs of Staff to the Commander in Chief, Far East (MacArthur),” Washington – November 6, 1950, 11:47 a.m., Foreign Relations of the United States, 1950, Korea, Volume VII, Office of the Historian, U.S. State Department, https://history.state.gov/historicaldocuments/frus1950v07/d758, and “The Joint Chiefs of Staff to the Commander in Chief, Far East (MacArthur),” Washington – November 6, 1950, 11:57 p.m., Foreign Relations of the United States, 1950, Korea, Volume VII, Office of the Historian, U.S. State Department, https://history.state.gov/historicaldocuments/frus1950v07/d773.
6
On Ukrainian mobilization policies and challenges during the war, see Simon Schlegel, “Mobilisation, Peacemaking and Deterrence in Ukraine,” International Crisis Group, December 17, 2024, https://www.crisisgroup.org/europe-central-asia/eastern-europe/ukraine/mobilisation-peacemaking-and-deterrence-ukraine, and Gil Barndollar, “The Deep Strike Dodge: Firepower and Manpower in Ukraine’s War,” War on the Rocks, February 26, 2025, https://warontherocks.com/2025/02/the-deep-strike-dodge-firepower-and-manpower-in-ukraines-war/.
7
A massive pre-emptive strike by Chinese missile forces against U.S. bases in the Western Pacific has been a central concern for U.S. defense planners since at least the mid-2010s. For early discussions of this prospect, see “Chinese Attacks on Air Bases in Asia: An Assessment of Relative Capabilities, 1996-2017,” RAND Corporation, September 2015, https://www.rand.org/pubs/research_briefs/RB9858z2.html, and Thomas Shugart and Javier Gonzalez, “First Strike: China’s Missile Threat to U.S. Bases in Asia,” Center for New American Security, June 2017, https://s3.us-east-1.amazonaws.com/files.cnas.org/hero/documents/CNASReport-FirstStrike-Final.pdf.
8
See, for example, Stacie Pettyjohn, Becca Wasser, and Chris Dougherty, “Dangerous Straits: Wargaming a Future Conflict over Taiwan,” Center for New American Security, June 2022, https://s3.amazonaws.com/files.cnas.org/CNAS+Report-Dangerous+Straits-Defense-Jun+2022-FINAL-print.pdf; Hal Brands, “Getting Ready for a Long War with China: The Dynamics of a Protracted Conflict in the Western Pacific,” American Enterprise Institute, June 2022, https://www.aei.org/wp-content/uploads/2022/07/Getting-Ready-for-a-Long-War-with-China-Dynamics-of-Protracted-Conflict-in-the-Western-Pacific.pdf?x85095; and Justin Cobb, “No One Should Think the War Will Be Short,” Proceedings, vol. 150, no. 9 (September 2024) https://www.usni.org/magazines/proceedings/2024/september/no-one-should-think-war-will-be-short.
9
Having introduced this notion, it is important to recognize that the impact of a U.S. loss on Pacific alliances or its regional standing is not necessarily clear cut. For a more fulsome examination of the potential consequences of the U.S. failing in a defense of Taiwan (or foregoing one altogether), see Michael A. Hunzeker and Mark A. Christopher, America’s Taiwan Dilemma: Allied Reactions and the Stakes for U.S. Reputation (Amherst: Cambria Press, 2025).
10
To provide one example, a series of wargames conducted by the Center for Strategic and International Studies (CSIS) in 2022 produced estimated losses on the U.S. side of thousands of dead, hundreds of aircraft destroyed, and dozens of naval vessels sunk, including two carriers in some excursions. As the summary report from the game noted, even though the United States had achieved a nominal victory, its losses undermined its global position moving forward. Although not explored in the CSIS game, presumably the impacts on U.S. standing would be even greater in the event of a defeat, one accompanied by even higher equipment and personnel losses. See Mark F. Cancian, Matthew Cancian, and Eric Heginbotham, “The First Battle of the Next War: Wargaming a Chinese Invasion of Taiwan,” Center for Strategic and International Studies, January 2023, 83, 101–102, https://www.csis.org/analysis/first-battle-next-war-wargaming-chinese-invasion-taiwan.
11
Sweeney, “Why a Taiwan Conflict Could Go Nuclear,” 5–6.
12
Francis J. Gavin, Nuclear Statecraft: History and Strategy in America’s Atomic Age (Ithaca: Cornell University Press, 2012) 30–56, Kindle edition.
13
Gavin, Nuclear Statecraft, 34, Kindle edition. See also, David Alan Rosenberg, “The Origins of Overkill: Nuclear Weapons and American Strategy, 1945–1960,” International Security, vol. 7, no. 2 (Spring 1983) 67–69, https://www.jstor.org/stable/2626731. For additional background on “massive retaliation,” see Lawrence Freedman and Jeffrey Michaels, The Evolution of Nuclear Strategy: New, Updated and Completely Revised (London: Palgrave Macmillan, 2019) 102–120, Kindle edition.
14
Gavin, Nuclear Statecraft, 33–40, Kindle edition.
15
As quoted in Bernard Brodie, Escalation and the Nuclear Option (Princeton: Princeton University Press, 1966) 12.
16
This section presents a very brief overview of early Cold War thinking on limited nuclear war, primarily using the positions of Kissinger and Brodie as representative examples. But it is by no means complete and a more fulsome discussion of the subject would, at a minimum, also include works by B.H. Liddel Hart, Morton Halperin, Robert Osgood, Thomas Schelling, and Albert Wohlstetter. For a deeper overview of thinking during this era on limited nuclear use, see Jeffrey A. Larsen, “Limited War and the Advent of Nuclear Weapons,” and Andrew L. Ross, “The Origins of Limited Nuclear War Theory,” in On Limited Nuclear War in the 21st Century, eds. Jeffrey A. Larsen and Kerry M. Kartchner, (Stanford: Stanford University Press, 2014) 3–48, Kindle edition. See also Freedman and Michaels, The Evolution of Nuclear Strategy, 121–154, Kindle edition.
17
Henry A. Kissinger, The Necessity for Choice (London: Chatto and Windus, 1960) 82–83.
18
See Brodie, Escalation and the Nuclear Option. Brodie’s ideas—essentially an early form of “escalate to de-escalate”—were first developed in a 1965 RAND memorandum, which served as the basis for his subsequent book. See also Bernard Brodie, “Escalation and the Nuclear Option,” RAND Corporation, Memorandum RM-4544-PR, June 1965, https://apps.dtic.mil/sti/pdfs/AD0624139.pdf.
19
When Brodie wrote in 1965, China had only tested its first fission bomb some months earlier and its missile programs were still quite immature. This restricted China to air delivery with the attendant limitations on range of deployment. China had no means to directly strike the U.S. homeland itself. On the slow pace of China’s development of nuclear-armed missiles, see Jeffrey Lewis, Paper Tigers: China’s Nuclear Posture (London: International Institute for Strategic Studies, 2014) 99–125.
20
Brodie, Escalation and the Nuclear Option, 113–134.
21
On the importance of Taiwan to the Chinese Communist Party and its senior leaders, see Avery Goldstein, “China’s Grand Strategy Under Xi Jinping: Reassurance, Reform, and Resistance,” International Security, vol. 45, no. 1 (Summer 2020) 173–174, https://doi.org/10.1162/isec_a_00383.
22
There is some debate over the exact number of Chinese-deployed nuclear weapons. In its most recent report to Congress, the Department of Defense states that China has actually surpassed 600 operational weapons; in contrast, analysts at the Bulletin of the Atomic Scientists argue that only 468 weapons are deployed, with 132 other warheads having been produced by China but still awaiting production of their delivery vehicles. However, there is general agreement between the two sources that China has at least 600 warheads in hand. See Hans M. Kristensen, Matt Korda, Eliana Johns, and Mackenzie Knight, “Chinese Nuclear Weapons, 2025,” Bulletin of the Atomic Scientists, vol. 81, no. 2, 135, https://doi.org/10.1080/00963402.2025.2467011, and U.S. Department of Defense, Military and Security Developments Involving the People’s Republic of China: Annual Report to Congress, December 2024, 101, https://media.defense.gov/2024/Dec/18/2003615520/-1/-1/0/MILITARY-AND-SECURITY-DEVELOPMENTS-INVOLVING-THE-PEOPLES-REPUBLIC-OF-CHINA-2024.PDF. (Hereafter, “Department of Defense, Annual Report to Congress, 2024.”) The U.S. warhead count is taken from Hans M. Kristensen, Matt Korda, Eliana Johns, and Mackenzie Knight, “United States Nuclear Weapons, 2025,” Bulletin of the Atomic Scientists, vol. 81, no. 1, 53, https://doi.org/10.1080/00963402.2024.2441624.
23
For additional background, see Kristensen et al, “United States Nuclear Forces, 2025,” 59–67. See also Ronald O’Rourke, Navy Columbia (SSBN-826) Class Ballistic Missile Submarine Program: Background and Issues for Congress, R41129, Congressional Research Service, updated March 18, 2025, https://www.congress.gov/crs-product/R41129; Anya L. Fink and Amy F. Woolf, “Defense Primer: LGM-35A Sentinel Intercontinental Ballistic Missile,” IF11681, Congressional Research Service, updated February 12, 2025, https://www.congress.gov/crs-product/IF11681; and “B-21 Raider,” United States Air Force, accessed March 31, 2025, https://www.af.mil/About-Us/Fact-Sheets/Display/Article/2682973/b-21-raider/.
24
Department of Defense, Annual Report to Congress, 2024, 105.
25
For general background in China’s SSBN program, see Tong Zhao, Tides of Change: China’s Strategic Ballistic Nuclear Submarines and Strategic Stability (Washington, DC: Carnegie Endowment for International Peace, 2018) https://carnegieendowment.org/files/Zhao_SSBN_final.pdf, and David C. Logan, “China’s Sea-Based Nuclear Deterrent: Organizational, Operational, and Strategic Implications,” Chinese Maritime Studies Institute, U.S. Naval War College, December 2023, https://digital-commons.usnwc.edu/cgi/viewcontent.cgi?article=1032&context=cmsi-maritime-reports. There are some indications China’s two most recent SSBNs have improved quieting, although not sufficient to approximate the best Russian and U.S. designs. See the discussion in Christopher P. Carlson and Howard Wang, “China Maritime Report No. 30: A Brief Technical History of PLAN Nuclear Submarines,” Chinese Maritime Studies Institute, U.S. Naval War College, August 2023, 17–18, https://digital-commons.usnwc.edu/cgi/viewcontent.cgi?article=1029&context=cmsi-maritime-reports.
26
Department of Defense, Annual Report to Congress, 2024, 56, 104.
27
“Table 1: Chinese Nuclear Forces, 2025,” in Kristensen et al, “Chinese Nuclear Forces, 2025,” 136.
28
Department of Defense, Annual Report to Congress, 2024, 63.
29
Department of Defense, Annual Report to Congress, 2024, 63.
30
Department of Defense, Annual Report to Congress, 2024, 101.
31
Kristensen et al, “Chinese Nuclear Forces, 2025,” 149.
32
This is a necessarily abbreviated discussion, which addresses two broad motivations for the expansion of the Chinese nuclear arsenal. Other more nuanced explanations can also be considered. See, for example, the exploration of six possible drivers of Chinese nuclear planning and their implications for future force structure in David C. Logan and Phillip C. Saunders, Discerning the Drivers of China’s Nuclear Force Development: Models, Indicators, and Data (Washington, DC: National Defense University Press, 2023) https://digitalcommons.ndu.edu/china-strategic-perspectives/1/. See also the important perspective offered in Tong Zhao, Political Drivers of China’s Changing Nuclear Policy: Implications for U.S.-China Nuclear Relations and International Security (Washington, DC: Carnegie Endowment for International Peace, 2024) https://carnegie-production-assets.s3.amazonaws.com/static/files/Zhao_Political%20Drivers_final-2024.pdf.
33
Lewis, Paper Tigers, 14, 15–18.
34
Lewis, Paper Tigers, 14, 50.
35
By 1992, China had just six ICBMs deployed capable of hitting the continental United States, two DF-5’s and four DF-5A’s. See John Wilson Lewis and Hua Di, “China’s Ballistic Missile Programs,” International Security, vol. 17. no. 2 (Fall 1992) 19, https://www.jstor.org/stable/2539167.
36
Matthew Kroenig, “Nuclear Superiority and the Balance of Resolve: Explaining Nuclear Crisis Outcomes,” International Organizations, vol. 67, no. 1 (Winter 2013) 131–171, https://www.jstor.org/stable/43282155.
37
This ratio is based on figures for the total estimated number of Chinese and U.S. operational nuclear weapons in Hans M. Kristensen and Matt Korda, “Chinese Nuclear Forces, 2020,” Bulletin of the Atomic Scientists, vol. 76, no. 6 (2020) 443, https://doi.org/10.1080/00963402.2020.1846432, and Hans M. Kristensen and Matt Korda, “United States Nuclear Forces, 2020,” Bulletin of the Atomic Scientists, vol. 76, no. 1 (2020) 46, https://doi.org/10.1080/00963402.2019.1701286.
38
U.S. Department of Defense, Military and Security Developments Involving the People’s Republic of China: Annual Report to Congress, November 2022, 94, https://www.defense.gov/Spotlights/2022-China-Military-Power-Report/.
39
There are alternate terms to “tactical” that can be used when discussing this type of nuclear weapon, including “theater,” “sub-strategic,” “nonstrategic,” or simply “low-yield.” Each of these may carry slightly different connotations but generally refer to a class of nuclear weapons below the strategic level. For simplicity and consistency, “tactical” is used throughout the remainder of the paper.
40
See the yields listed in “Table 1: United States Nuclear Forces, 2025,” in Kristensen et al, “United States Nuclear Forces, 2025,” 54; “Table 1: Chinese Nuclear Forces, 2025,” in Kristensen et al, “Chinese Nuclear Forces, 2025,” 136; and “Table 1: Russian, Nuclear Forces, 2024,” in Hans M. Kristensen, Matt Korda, Eliana Johns, and Mackenzie Knight, “Russian Nuclear Forces, 2024,” Bulletin of the Atomic Scientists, vol. 80, no. 2, 119, https://doi.org/10.1080/00963402.2024.2314437.
41
See the discussion of definitional issues related to tactical weapons in Paul Schulte, “Tactical Nuclear Weapons in NATO and Beyond: A Historical and Thematic Examination,” in Tactical Nuclear Weapons and NATO, eds. Tom Nichols, Douglas Stuart, and Jeffrey D. McCausland (Carlisle: Strategic Studies Institute, 2012) 13–15, https://www.hsdl.org/?view&did=706112.
42
This point is also made in Schulte, “Tactical Nuclear Weapons and Beyond,” 14. Bomb yield taken from “Atomic Bombing of Hiroshima,” The Manhattan Project: Interactive History, U.S. Department of Energy, accessed March 19, 2024, https://www.osti.gov/opennet/manhattan-project-history/Events/1945/hiroshima.htm.
43
“Atomic Bombing of Hiroshima,” U.S. Department of Energy.
44
For background, see Schulte, “Tactical Nuclear Weapons in NATO and Beyond,” 14–74, and Edward L. Warner, III, Soviet Concepts and Capabilities for Limited Nuclear War: What We Know and How We Know It (Santa Monica: RAND Corporation, 1989) https://www.rand.org/content/dam/rand/pubs/notes/2007/N2769.pdf.
45
See Susan J. Koch, The Presidential Nuclear Initiatives of 1991-1992 (Washington, DC: National Defense University Press, 2012) https://ndupress.ndu.edu/portals/68/documents/casestudies/cswmd_casestudy-5.pdf.
46
Kristensen et al, “United States Nuclear Forces, 2025,” 54, 69.
47
Kristensen et al, “United States Nuclear Forces, 2025,” 54, 69.
48
Thomas Newdick, “F-35A Is Officially Certified For Nuclear Strike,” War Zone, March 9, 2024, https://www.twz.com/air/f-35a-is-officially-certified-for-nuclear-strike.
49
Kristensen et al, “United States Nuclear Forces, 2025,” 67–68.
50
Kristensen et al, “United States Nuclear Forces, 2025,” 54, 65.
51
Kristensen et al, “United States Nuclear Forces, 2025,” 54, 65.
52
Kristensen et al, “United States Nuclear Forces, 2025,” 54, 65.
53
For two alternate perspectives on the W76-2 and launch ambiguity, see Vipin Narang, “The Discrimination Problem: Why Putting Low-Yield Nuclear Weapons on Submarines Is So Dangerous,” War on the Rocks, February 8, 2018, https://warontherocks.com/2018/02/discrimination-problem-putting-low-yield-nuclear-weapons-submarines-dangerous/, and Austin Long, “Discrimination Details Matter: Clarifying an Argument About Low-Yield Nuclear Warheads,” War on the Rocks, February 16, 2018, https://warontherocks.com/2018/02/discrimination-details-matter-clarifying-argument-low-yield-nuclear-warheads/.
54
“Table 1: United States Nuclear Forces, 2025,” in Kristensen et al, “United States Nuclear Forces, 2025,” 54.
55
See the discussion on AGM-86 survivability in Matthew R. Costlow, “The Value of the LRSO in an Uncertain Future Environment,” National Institute for Public Policy, February 28, 2019, 2–4, https://nipp.org/wp-content/uploads/2021/03/IS-438.pdf.
56
“W80-4 Life Extension Program,” National Nuclear Security Administration, accessed March 21, 2025, https://www.osti.gov/servlets/purl/1357921.
57
“Selected Acquisition Report (SAR): Long Range Standoff (LRSO) Weapon,” U.S. Department of Defense, December 2022, 8, https://www.esd.whs.mil/Portals/54/Documents/FOID/Reading%20Room/Selected_Acquisition_Reports/FY_2022_SARS/LRSO_SAR_DEC_2022.pdf.
58
Anya L. Fink and Amy F. Woolf, “Nuclear-Armed Sea-Launched Cruise Missile (SLCM-N),” IF12084, Congressional Research Service, updated February 12, 2025, 1, https://www.congress.gov/crs-product/IF12084.
59
See comments by Vice Admiral Johnny Wolfe, Jr., director, Strategic Systems Program, United States Navy, in Sydney J. Freedberg, Jr., “Sub-Launched Nuclear Cruise Missile Will Need ‘An Entirely New Industrial Base,’ Warns Navy Admiral,” Breaking Defense, November 15, 2024, https://breakingdefense.com/2024/11/sub-launched-nuclear-cruise-missile-will-need-an-entirely-new-industrial-base-warns-navy-admiral/.
60
See, for example, Matthew Kroenig, “Deliberate Nuclear Use in a War over Taiwan: Scenarios and Considerations for the United States,” Atlantic Council, September 2023, https://www.atlanticcouncil.org/wp-content/uploads/2023/10/Kroenig-Deliberate-Nuclear-Use-in-a-War-over-Taiwan.pdf; Greg Weaver, “The Role of Nuclear Weapons in a Taiwan Crisis,” Atlantic Council, November 2023, https://www.atlanticcouncil.org/wp-content/uploads/2023/11/Weaver-Role-of-Nuclear-Weapons-in-Taiwan-Crisis.pdf; and Andrew Metrick, Philip Sheers, and Stacie Pettyjohn, “Over the Brink: Escalation Management in a Protracted War,” Center for New American Security, August 2024, https://s3.us-east-1.amazonaws.com/files.cnas.org/documents/Over-the-Brink-Defense-August-2024-FINAL.pdf.
61
For the sake of accuracy, it should be noted that China possessed some gravity bombs during the Cold War era whose lower yield was in accordance with the broad definition of tactical weapons. However, these bombs were among the first produced by China’s nuclear weapons program, and their lower yield was likely the result of technological limitations rather than a deliberate effort to develop a battlefield weapon. China also tested an enhanced radiation weapon (or “neutron bomb”) in the 1980s but does not seem to have ever fielded an operational capability. Neither the lower-yield gravity bombs nor the neutron bomb is in China’s current nuclear inventory. See Lewis, Paper Tigers, 55–58; Phillip C. Saunders and David C. Logan, “China’s Regional Nuclear Capability, Nonnuclear Systems, and Integration of Concepts and Operations,” in China’s Strategic Arsenal: Worldview, Doctrine, and Systems, eds. James M. Smith and Paul J. Bolt (Washington, DC: Georgetown University Press, 2021) 125, and Kristensen et al, “Chinese Nuclear Forces, 2025,” 146, 154–155.
62
Department of Defense, Annual Report to Congress, 2024, 110, and Weaver, “The Role of Nuclear Weapons in a Taiwan Crisis,” 6.
63
Saunders and Logan, “China’s Regional Nuclear Capability, Nonnuclear Systems, and Integration of Concepts and Operations,” 127.
64
Kristensen et al, “Chinese Nuclear Forces, 2025,” 140.
65
Logan and Saunders, Discerning the Drivers of China’s Nuclear Force Development, 2, 30.
66
See, for example, Office of the Secretary of Defense, Nuclear Posture Review, February 2018, 7–8, https://media.defense.gov/2018/feb/02/2001872877/-1/-1/1/executive-summary.pdf. For an overview of Russian tactical capabilities, see also Kristensen et al, “Russian Nuclear Forces, 2024,” 119, 134–135.
67
This is not to argue that thinking on nuclear matters was entirely dormant during these years, but certainly attention to questions of tactical use against another nuclear-armed power diminished in importance, even as other considerations for limited nuclear use—such as regional powers armed with chemical and biological weapons—emerged. See Paul I. Bernstein, “U.S. Post-Cold War Nuclear Strategy,” in On Limited Nuclear War in the 21st Century, 80–97, Kindle edition.
68
Paul K. Davis, J. Michael Gilmore, David R. Frelinger, Edward Geist, Christopher K. Gilmore, Jenny Oberholtzer, and Danielle C. Taraff, Exploring the Role Nuclear Weapons Could Play in Deterring Russian Threats to the Baltic States (Santa Monica: RAND Corporation, 2019) https://www.rand.org/pubs/research_reports/RR2781.html. See also David A. Shlapak and Michael W. Johnson, Reinforcing Deterrence on NATO’s Eastern Flank (Santa Monica: RAND Corporation, 2016) https://www.rand.org/pubs/research_reports/RR1253.html.
69
See the discussion in Davis et al, Exploring the Role Nuclear Weapons Could Play in Deterring Russian Threats to the Baltic States, 74–79.
70
Saunders and Logan, “China’s Regional Nuclear Capability, Nonnuclear Systems, and Integration of Concepts and Operations,” 125.
71
Population density determined using figures from “Taiwan – Country Factsheet,” The World Factbook, Central Intelligence Agency, accessed March 21, 2025, https://www.cia.gov/the-world-factbook/countries/taiwan/factsheets/.
72
On the challenges of tactical employment near friendly troops, see Theodore A. Postol, “Targeting,” in Managing Nuclear Operations, eds. Ashton B. Carter, John D. Steinbruner, and Charles A. Zraket (Washington, DC: Brookings Institution, 1987) 402–404.
73
Kroenig, “Deliberate Nuclear Use in a War over Taiwan,” 10, and Weaver, “The Role of Nuclear Weapons in a Taiwan Crisis,” 12. See also the recommendation for the United States to acquire new tactical nuclear weapons optimized for use against ships in Metrick, Sheers, and Pettyjohn, “Over the Brink,” 15.
74
An important source of information on nuclear weapons effects at sea is the Crossroads nuclear tests conducted by the U.S. Navy at Bikini Atoll in 1946. The tests subjected decommissioned naval vessels to actual nuclear detonations. See Operation Crossroads 1946, Defense Nuclear Agency (DNA 60322F) https://apps.dtic.mil/sti/tr/pdf/ADA146562.pdf. See also Charles R. Jones, “Weapon Effects Primer,” Proceedings, vol. 104, no. 1 (January 1978) https://www.usni.org/magazines/proceedings/1978/january/weapon-effects-primer.
75
Jones, “Weapon Effects Primer.”
76
Weaver, “The Role of Nuclear Weapons in a Taiwan Crisis,” 12.
77
Weaver, “The Role of Nuclear Weapons in a Taiwan Crisis,” 13.
78
Ian Easton, The Chinese Invasion Threat: Taiwan’s Defense and American Strategy in Asia (Manchester: Eastbridge Books, 2017) 134–135.
79
See “Chinese Attacks on Air Bases in Asia,” RAND Corporation; Shugart and Gonzalez, “First Strike”; and Kelly A. Grieco, Hunter Slingbaum, and Jonathan M. Walker, Cratering Effects: Chinese Missile Threats to U.S. Air Bases in the Indo-Pacific, Stimson Center, December 2024, https://www.stimson.org/2024/cratering-effects-chinese-missile-threats-to-us-air-bases-in-the-indo-pacific/.
80
Department of Defense, Annual Report to Congress, 2024, 87.
81
For example, one open-source study of potential Chinese attacks on U.S. airbases in the Western Pacific found they were significantly more effective in the First Island Chain than in the Second Island Chain, with air operations disrupted for nearly 12 days in the case of attacks against bases in Japan as opposed to less than two days in the case of Guam. See Grieco, Slingbaum, and Walker, Cratering Effects, 8.
82
See “Chart: Fielded Conventional Strike,” in Department of Defense, Annual Report to Congress, 2024, 67.
83
See Mike Sweeney, “Challenges to Chinese Blue-Water Operations,” Defense Priorities, April 2024, https://www.defensepriorities.org/explainers/challenges-to-chinese-blue-water-operations/.
84
Department of Defense, Annual Report to Congress, 2024, 53.
85
Department of Defense, Annual Report to Congress, 2024, 65.
86
Other examples of potential nuclear employment in a Western Pacific war could include use by China against Taiwanese forces on Taiwan itself, use by either side against an opponent’s aircraft carriers, or use by either side in the upper atmosphere to destroy space-based sensors and communication satellites.
87
Thomas C. Schelling, “Foreword,” in On Limited Nuclear War in the 21st Century, Kindle edition. See also Thomas C. Schelling, Nuclear Weapons and Limited War (Santa Monica: RAND Corporation, 1959).
88
Desmond Ball, “Nuclear War at Sea,” International Security, vol. 10, no. 3 (Winter 1985–1986) 8–10, https://www.jstor.org/stable/2538940/.
89
See, for example, Pettyjohn, Wasser, and Dougherty, “Dangerous Straits”; Metrick, Sheers, and Pettyjohn, “Over the Brink”; and Mark Cancian, Mathew Cancian, and Eric Heginbotham, “Confronting Armageddon: Wargaming Nuclear Deterrence and Its Failures in a U.S.-China Conflict over Taiwan,” Center for Strategic and International Studies and the MIT Wargaming Lab, December 2024, https://www.csis.org/analysis/confronting-armageddon.
90
See comments by Becca Wasser beginning at 21:00 in “War Game in Taiwan,” Chuck Toddcast, May 13, 2022, https://www.cnas.org/publications/podcast/war-game-in-taiwan-a-home-game-for-china-an-away-game-for-the-u-s.
91
In addition to the limitations inherent in accurately reproducing the views and perspectives of senior Chinese leaders, there also is a broader challenge of recreating the psychological and emotional demand of nuclear decision-making in a game environment. As Bernard Brodie observed 60 years ago on the value of nuclear wargames, “In this pursuit we are dealing with issues of human behavior under great emotional stress in circumstances that have never been experienced… Use of techniques like war gaming or crisis gaming helps to enlarge the perspectives of the players and to make them more comprehensive in their thinking, but it provides neither them nor those who read their reports with answers to the crucial questions. Experienced persons agree that one simply cannot reproduce among the players in a gaming environment the kind and degree of emotional tension and feeling of high responsibility bound to be present in the nuclear era among decision-makers in real-life crises, where decisions have to be made about whether and by what means to fight a war. In games, erroneous moves are free of penalties of the required magnitude; the appropriate fear or dread of both sides is thus only dimly imagined, and feelings of anger or hostility may be exaggerated in importance.” Brodie, Escalation and the Nuclear Option, 37–38.
92
While a thorough analysis of the performance of active missile defenses in Ukraine and Israel has yet to be undertaken, preliminary assessments are offered in Jen Judson, “How Patriot Proved Itself in Ukraine and Secured a Fresh Future,” Defense News, April 9, 2024, https://www.defensenews.com/land/2024/04/09/how-patriot-proved-itself-in-ukraine-and-secured-a-fresh-future/; Sinéad Baker, “Ukraine’s Patriot Kills of Russian Planes and Missiles Have Turned a U.S. Air-Defense Weapon with a Troubled Past into a Hero,” Business Insider, May 23, 2024, https://www.businessinsider.com/patriot-performance-in-ukraine-dispels-doubts-over-abilities-experts-2024-3; Matthew Saville, “Iran’s Missile Attack is a Challenge Israel Can’t Ignore,” Royal United Services Institute, October 2, 2024, https://www.rusi.org/explore-our-research/publications/commentary/irans-missile-attack-challenge-israel-cant-ignore; and Michael Knights and Elizabeth Dent, “Israel’s Missile Defense Performance: Views from the Gulf,” Washington Institute for Near East Policy, October 11, 2024, https://www.washingtoninstitute.org/policy-analysis/israels-missile-defense-performance-views-gulf.
93
For an extended overview of the Guam defense system, see Gerry Doyle, Vijdan Mohammad Kawoosa, and Arathy J. Aluckal, “Island in the Crosshairs,” Reuters, December 10, 2024, https://www.reuters.com/graphics/USA-CHINA/GUAM/myvmbqngnpr/.
94
See comments by Lt. Gen. Heath Collins, director, U.S. Missile Defense Agency, in Sydney F. Freedberg, Jr., “‘Mind-boggling’: Israel, Ukraine Are Mere Previews of a Much Larger Pacific Missile War, Officials Warn,” Breaking Defense, April 24, 2024, https://breakingdefense.com/2024/04/mind-boggling-israel-ukraine-are-mere-previews-of-a-much-larger-pacific-missile-war-officials-warn/.
95
For example, insufficient stockpiles of the Navy’s Standard Missiles are examined in Mackenzie Eaglen, “The U.S. Navy’s Missile Production Problem Looks Dire,” American Enterprise Institute, July 8, 2024, https://www.aei.org/op-eds/the-u-s-navys-missile-production-problem-looks-dire/.
96
See Joseph Trevithick, “Russia’s Experimental Ballistic Missile Used To Strike Ukraine Is Based On The RS-26 Rubezh,” War Zone, November 21, 2024, https://www.twz.com/land/russias-experimental-ballistic-missile-used-to-strike-ukraine-is-based-on-the-rs-26-rubezh.
97
For example, the current ground-based interceptor has a success rate only slightly better than 50 percent in flight-test intercepts, achieving hits in just 12 out 21 tries. See “U.S. Missile Defense Test Record,” Missile Defense Advocacy Alliance, March 2023, https://missiledefenseadvocacy.org/missile-defense-systems-2/missile-defense-intercept-test-record/u-s-missile-defense-intercept-test-record/.
98
Hannah D. Dennis, “Defense Primer: U.S. Ballistic Missile Defense,” IF10541, Congressional Research Service, updated December 30, 2024, 2, https://www.congress.gov/crs-product/IF10541.
99
Some analysts have questioned the effectiveness of GMD even if one allows for launching multiple interceptors against a single warhead. See, for example, Ankit Panda and Vipin Narang, “Deadly Overconfidence: Trump Thinks Missile Defenses Work Against North Korea, and That Should Scare You,” War on the Rocks, October 16, 2017, https://warontherocks.com/2017/10/deadly-overconfidence-trump-thinks-missile-defenses-work-against-north-korea-and-that-should-scare-you/.
100
This discussion focuses on Australia, Japan, the Philippines, and South Korea. Thailand is a fifth U.S. treaty ally in Asia, although it is not expected to play any meaningful role in a war over Taiwan.
101
For example, in recent years, the U.S. Air Force has routinely conducted deployments of its B-2 stealth bombers to Australia’s Amberley airbase, near Brisbane, while there are plans under the AUKUS agreement to forward-base U.S. attack submarines at HMS Sterling, near Perth, on a rotational basis. See Oliver Parken, “20 Percent Of The USAF’s B-2 Force Is Deployed ‘Down Under,’” War Zone, August 4, 2022, https://www.twz.com/20-percent-of-the-usafs-b-2-force-is-deployed-down-under, and Kirsty Needham, “U.S. Starts to Build Submarine Presence on Strategic Australian Coast under AUKUS,” Reuters, March 17, 2025, https://www.reuters.com/business/aerospace-defense/us-starts-build-submarine-presence-strategic-australian-coast-under-aukus-2025-03-16/.
102
See Jeffrey W. Hornung, Kristen Gunness, Bryan Rooney, Dan McCormick, Lydia Grek, Ryan A. Schwankhart, Gian Gentile, and Marisa R. Lino, Fighting from an Ally’s Land: Challenges and Opportunities for U.S. Forces in the Indo-Pacific (Santa Monica: RAND Corporation, 2024) 70–77.
103
For detailed examinations of the possible response of regional allies to a Taiwan conflict, see Hornung et al, Fighting Abroad from an Ally’s Land, and Hunzeker and Christopher, America’s Taiwan Dilemma.
104
See “Nuclear Planning Group (NPG),” North Atlantic Treaty Organization, updated May 9, 2022, https://www.nato.int/cps/em/natohq/topics_50069.htm. For additional background on the NPG’s development and role in NATO, see also Timothy Andrew Sayles, “A Nuclear Education: The Origins of NATO’s Nuclear Planning Group,” Journal of Strategic Studies, vol. 43, no. 6–7 (2020) 920–956, https://doi.org/10.1080/01402390.2020.1818560/, and Simon Lunn, “NATO Nuclear Sharing,” in Building a Safe, Secure, and Credible NATO Nuclear Posture, eds., Steve Andreasen, Isabelle Williams, Brian Rose, Hans M. Kristensen, and Simon Lunn (Washington, DC: The Nuclear Threat Initiative, 2018) http://www.jstor.com/stable/resrep17630.12.
105
See the discussion in Elbridge A. Colby, “U.S. Nuclear Weapons Policy and Policymaking: The Asian Experience,” in Tactical Nuclear Weapons and NATO, 87–94.
106
This discussion benefits from the author’s interactions with Dr. Michael A. Hunzeker of the Schar School of Policy and Government on his research into allied perceptions of potential U.S. involvement in a Taiwan conflict. See also Hunzeker and Christopher, America’s Taiwan Dilemma.

Author

Mike
Sweeney

Non-Resident Fellow

Defense Priorities

On limited nuclear use in the Western Pacific

Introduction

On first use

Question 1: Would a war over Taiwan remain limited?

Question 2: Is limited nuclear use compatible with limited war?

Question 3: How do the Chinese and U.S. nuclear arsenals compare?

Question 4: Why is China expanding its nuclear arsenal?

Question 5: What tactical nuclear weapons do China and the United States have?

Question 6: How would tactical nuclear weapons affect a Taiwan conflict?

Question 7: Would China or the United States benefit more from limited nuclear employment?

Question 8: Do China and the United States understand each other’s nuclear red lines?

Question 9: How would missile defenses impact nuclear use?

Question 10: How would U.S. Pacific allies react to nuclear use?

Summary thoughts

Endnotes

Author

Mike
Sweeney

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Expert updates and analysis to enhance your understanding of vital U.S. national security issues

On limited nuclear use in the Western Pacific

Introduction

On first use

Question 1: Would a war over Taiwan remain limited?

Question 2: Is limited nuclear use compatible with limited war?

Question 3: How do the Chinese and U.S. nuclear arsenals compare?

Question 4: Why is China expanding its nuclear arsenal?

Question 5: What tactical nuclear weapons do China and the United States have?

Question 6: How would tactical nuclear weapons affect a Taiwan conflict?

Question 7: Would China or the United States benefit more from limited nuclear employment?

Question 8: Do China and the United States understand each other’s nuclear red lines?

Question 9: How would missile defenses impact nuclear use?

Question 10: How would U.S. Pacific allies react to nuclear use?

Summary thoughts

Endnotes

Author

Mike Sweeney

More on Asia

Events on China

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