Understanding the Deterrence Gap in the Taiwan Strait
What is stopping China from invading Taiwan? In the past, it was overdetermined that Beijing would not use force to compel reunification. Not only did China lack the capabilities to execute a swift and decisive conquest of the island, but China’s leaders since 1979 used to believe that peaceful unification was both possible and vastly more preferable to military solutions. Today, however, the military balance of power has shifted decisively, enabling an amphibious invasion from a capabilities standpoint in the not-too-distant future, while prospects of peaceful unification have faded. As such, it is now something of a conventional wisdom that a Chinese invasion has become more likely than not.
We agree with these pessimistic assessments. Of course, no analyst can say with certainty when or why a war over Taiwan might be triggered. Those who project auras of inevitability are wrong to do so. But the changing geopolitical situation around Taiwan cannot be ignored. It is only because deterrence across the Taiwan Strait was strong that past crises over the island’s political status could unfold without causing an invasion. Now that deterrence has weakened, there are few if any guardrails to prevent current or future crises from escalating to become a full-blown war.
This is a combustible situation — one that warrants urgent attention from Taiwanese and American leaders. For Taiwan to regain security, the deterrence gap should be closed and the odds of destabilizing crises emerging should be lowered.
What Is Making War More Likely?
The balance of power across the Taiwan Strait used to serve as a tight constraint on China’s freedom of maneuver. In the past, Taiwan’s armed forces — especially its air force — constituted a significant barrier to a Chinese invasion. As recently as 2002, the Department of Defense’s report to Congress on Chinese military power assessed that Taiwan’s air force enjoyed “dominance of the airspace over the Taiwan Strait” and maintained “a qualitative edge over” its Chinese counterpart. But this is no longer the case.
To be sure, China still has reason to fear a U.S. military intervention in a war over Taiwan, but the threat of such an intervention has been made deliberately uncertain. It would be wrong to dismiss “strategic ambiguity” as a dud deterrent. But it is becoming increasingly clear it may not be sufficient on its own to deter an invasion.
This is because Chinese strategists have had decades to plan for this eventuality. As a result, the United States no longer possesses clear escalation dominance. People’s Liberation Army doctrine is optimistic about managing escalation, which perhaps increases the likelihood of a first strike against forward-deployed U.S. assets in East Asia of the sort that might significantly undermine U.S. capabilities for stopping an invasion. And, of course, there is always the possibility that nuclear-armed China could successfully deter Washington from joining a conflict over Taiwan, as Russia has in Ukraine.
Various “self-deterrents” that once held back China have weakened, too. For example, leaders in Beijing once worried that absorbing Taiwan into the People’s Republic would pose significant social, political, and economic challenges — so much so that unification was sometimes viewed as more trouble than it was worth, at least in the short term. Not anymore.
At the same time as the balance of power has shifted, Chinese government incentives for restraint have also eroded. Those who talk about deterrence usually focus on the credibility and potency of threats made against a potential aggressor — that is, an adversary’s expectations about what will befall them if they do something unwanted. But such constraints are only part of a would-be aggressor’s overall calculation about whether to use force. States also consider what will happen to their political, social, and economic interests if they do not use force.
The 2022 National Defense Strategy put incentives for restraint at the heart of the concept of deterrence:
Deterrence is strengthened by actions that reduce a competitor’s perception of the benefits of aggression relative to restraint. Effective deterrence requires the Department to consider how competitors perceive U.S., Ally, and partner stakes, commitment, and combat credibility; their perception of their own ability to control escalation risks; and their view of how the status quo will evolve – in part as a result of U.S., Ally, and partner actions – if they do not use force.
This sophisticated understanding of deterrence is directly applicable to assessing Chinese government decision-making today.
What are the costs to China of exercising restraint? With reference to Taiwan, we think four key variables speak to this point: the strength and resilience of the “One China” discursive framework; the rate of economic growth in China; the trajectory of “tech wars” involving the United States, Taiwan, China, and other relevant economies; and China’s perception of a closing window of opportunity to resolve the Taiwan dispute on favorable terms.
Restraint Variable 1: “One China”
Since the Shanghai Communique in 1972, a “One China” framework has been at the foundation of U.S.-Chinese relations. Of course, there has never been agreement over what the One China concept means, precisely. Beijing has a One China principle, for example, while the United States maintains a One China policy — with each capturing very different political understandings regarding the status of Taiwan.
But even so, the common language of “One China” has served as a useful discursive framework to help mediate the deep estrangement that defined ties between the United States and the Chinese Communist Party before 1972. The One China framework worked in the past because all sides tolerated — albeit sometimes more, sometimes less — the ambiguity that accompanied the compromise.
Since 2016, the One China idea has become increasingly devoid of practical meaning. This began to some extent haphazardly, with President-elect Donald Trump speaking with Taiwan’s president on the phone, but since then a bipartisan pattern of disregard has become the norm in U.S. politics. In our new monograph, Deterrence Gap: Avoiding War in the Taiwan Strait, we count 27 “firsts” since 1979 that have occurred since Trump’s phone call with Tsai Ing-wen in 2016. These “firsts” range from Taiwan’s chief of the general staff visiting the White House, to deputy assistant secretaries of defense visiting Taiwan, to the State Department terminating previous restrictions on U.S. government contacts with Taiwanese officials.
To be clear, for many of these developments, action-reaction cycles are in operation. We do not hold the Chinese government guiltless in the process that is destroying the status quo. Quite the contrary. But what matters for our present argument is this: Chinese analysts increasingly fear that the United States will reverse its One China policy and create a de jure or de facto defense alliance with Taiwan. This makes peace — and restraint — less beneficial for China in the short to medium term and creates powerful incentives for China to seek a non-peaceful resolution of the Taiwan dispute before the situation (from the Chinese Communist Party’s perspective) further deteriorates.
Restraint Variable 2: Economic Trends
The Chinese Communist Party rules China by mixing strategies of co-optation and coercion with claims to legitimacy. Over the past generation, legitimacy has been directly connected in China to economic performance. However, some observers now strongly suspect that economic growth in China has plateaued. This spells danger for cross-strait relations. For although we are skeptical of pure “diversionary war” arguments, slowing growth is important for a few reasons.
First, the erosion of economic competence as a hallmark of Communist Party rule might push China’s leaders to become more indulgent of nationalist pressure as a means of shoring up domestic support. Second, slowing growth means that there is a diminishing chance of Taiwan’s citizens opting to join the People’s Republic for some sort of economic payoff — something that was at least plausible in the not-too-distant past.
Finally, China’s economic slowdown threatens military spending as the Chinese state runs into a fiscal cliff by mid-century. This means that time will not solve all of China’s problems vis-à-vis Taiwan. On the contrary, time might be running out to make a move on Taiwan during propitious conditions.
Restraint Variable 3: Tech Wars
America’s export controls on semiconductors and related technologies are intended to prevent China from overtaking U.S. military, science, and technology power. In effect, Washington has launched a direct challenge to the Chinese government’s “innovation-driven development” strategy. The logic to these controls seems straightforward: Why should China’s economy and military benefit from technologies largely designed in the West and manufactured in Taiwan?
Counterintuitively, however, export controls might have some unintended consequences — namely, by decreasing the net costs of a Chinese invasion of Taiwan in the short term while creating pressures for Beijing to act before the U.S. military can reap the rewards of the emerging military-technological revolution. These dangerous side-effects of the tech war have been almost universally overlooked despite hefty international relations literature on economic interdependence and the expected costs of war.
In the past, one of the deterrents that protected Taiwan from invasion was the so-called “Silicon Shield.” The gist of the shield was that Taiwan’s position at the heart of the global semiconductor industry would add huge economic costs to a Chinese invasion. Although this in itself may be inadequate to deter such an invasion, it was one of a cluster of deterrents that operated in a concurrent and overlapping fashion, ensuring that the likely costs of an invasion outweighed the perceived benefits.
But restricting the export of semiconductors to China from Taiwan is entirely at odds with the Silicon Shield. In effect, China is being made to bear in peacetime the costs that it otherwise would have suffered only in wartime.
Even worse, the export controls impose additional time pressures on China writ large. The costs of recreating the technologies involved in extreme ultraviolet lithography are tremendous. As a former deputy director of the White House Office of Science and Technology Policy put it, “At some point, you’re replicating all of human civilization.” The allure of just taking such machines, the majority of which are located in Taiwan, may seem simpler.
Another form of this pressure is military, as the People’s Liberation Army watches others — with easy access to massive compute — “intelligentize” faster than it, contributing to a “better now than later” dynamic, which we consider a final key variable reducing Chinese restraint.
Restraint Variable 4: The Future Balance of Power
The general context for a potential closing window of opportunity is set by the plateauing of the Chinese economy and the likelihood it will not be able to fully exploit the current military-technical revolution due to export controls. These trends suggest that, over the long term, time may not be on China’s side. What about in the shorter term? There is good reason to see relative Chinese military power as peaking this decade. Despite the increasing alarm animating both military and civilian analysts, by some metrics U.S. military power is actually declining this decade due to where the United States is in its modernization cycles.
This is especially true of the Navy. According to the Congressional Budget Office, which analyzed three possible plans submitted to Congress by the Department of Defense for 2023: “the lethality of the fleet, as measured in part by the total number of missile cells, would decline by 13 percent until 2032.” This number includes both vertical launch cells and torpedo tubes. The falling numbers for this decade contrast in particular with the numbers projected after the 2020s, when “the number of torpedo tubes would increase, compared with the number in today’s fleet, by 40 percent to 50 percent.”
The Air Force, in contrast, does not face such a drastic decline in lethality, but the most significant system it is investing in for modern peer-on-peer warfare, the B-21, will not be available in mass until the 2030s. The B-21 will recapitalize capability that has atrophied over decades, as the Air Force became centered around short-range fighters not particularly suited to stopping a Chinese invasion of Taiwan.
For their parts, the Marine Corps and Army are both modernizing their force structures and training to be more relevant for the Taiwan “pacing scenario,” and by the 2030s both are likely to possess significant new formations and capabilities. At the same time, the results of Japan moving defense spending from 1 percent of GDP to 2 percent will begin to be felt, too, as will rising defense budgets and longer conscription terms in Taiwan.
The Chinese government, of course, will not stand still throughout the 2020s. Certainly, more Renhai Cruisers and J-20 fighters will be commissioned. But such incremental Chinese progress will not change the overall pattern, which is that China has mostly completed a modernization cycle begun in the late 1990s, while the United States is still in the midst of one. A reinvigorated U.S. Navy increasingly centered on submarines and smaller combatants instead of hugely expensive and potentially vulnerable aircraft carriers, an Air Force with long-range bombers, and a Marine Corps and Army with long-range missiles and dispersible capabilities poses a much more significant threat to an invading Chinese force than exists today — or this decade.
In all, the combination of eroding constraints and loosening restraints is a toxic mix, implying that whatever might have been doing the heavy lifting of dissuading China’s leaders from invading Taiwan in the past is likely not operating today. Given the high probability for major provocations relating to the Taiwan issue going forward, especially as Taiwan’s Democratic Progressive Party enters an unprecedented third presidential term in a row, and that fact that two recent pollssuggest that more than half of China’s population already support armed unification, the upshot is that the Chinese leadership is becoming less likely to act with restraint compared to the past.
Restoring Deterrence
In a previous article published in Parameters, we proposed a strategy for Taiwan to deter a Chinese invasion, one that did not rely on an uncertain U.S. military intervention. This comprised four main elements: A pre-planned resistance campaign, multilateral economic sanctions, regional balancing behavior, and a targeted campaign of scorched tech that would see Taiwan threaten to destroy or disable their semiconductor industry if China were to invade. These are all deterrents that Taiwan and its friends could develop quickly. Even if not as severe as a U.S. threat to intervene on Taiwan’s behalf, they are credible deterrents in the sense that China could have a high degree of confidence in these threats actually being carried out in response to an armed attack.
Beyond these ideas, what else can be done to repair deterrence, bolster reassurance, and avoid war?
The most important point, as we argue in our follow-up monograph, Deterrence Gap, is that Taiwan and its partners should not repeat the mistakes of the past by assuming deterrence to be fixed and immutable. It is not. All deterrents decay over time, and deterrence across the strait will be in a state of peak decay this decade. Taiwan and its friends should realize the gravity of the situation. They need quick fixes — potent and credible deterrents that will cause China’s leaders to question their ability to seize Taiwan in a fait accompli. Betting too heavily on deterrents that will come online next decade might actually increase risk this decade by generating a “better now than later dynamic.” And all concerned should avoid the siren call of symbolism, which provokes, over substance, which deters.
This decade, there is still low hanging (substantive) fruit that should be exploited. Taiwan’s political leaders should consider allowing the Taiwanese air force to change its intercept doctrine so it does not wear out its pilots and airframesby intercepting every Chinese flight into its Air Defense Identification Zone. The Taiwanese air force could also prioritize its air defense mission: denying the People’s Liberation Army Air Force command of the air would be vital in a conflict, and ground-based launchers will be more suitable for this than expensive fighters. As well, procuring and training across services to achieve massed precision fires will be key to challenge the People’s Republic of China’s defensive systems in an invasion.
Unfortunately, given the huge cost and long timeline for entering service, Taiwan’s much ballyhooed submarine programis likely a distraction from the fundamentals of developing the hardware and software for an effective “anti-navy.” Taiwan’s armed forces should instead prioritize the acquisition, production, and employment of mines, drones, and missiles. Mines are likely Taiwan’s best way to “buy time” with minimal risk to Taiwan’s armed forces, while drones could bolster Taiwan’s defenses via decentralized and attritable systems that could wreak havoc on an invading force, and missiles —especially if road-mobile — combine resilience with lethality. Russia’s war in Ukraine has shown that such systems would need to be accessible in mass (i.e., thousands not scores).
Taiwan should also continue building out access to a reliable low-earth orbit satellite network to help preserve communication ability in the event of a blockade or invasion, but it should prioritize systems resilience in this process. All of these actions are practical in the next few years. The only thing required is prioritization.
Finally, regional powers — especially Japan, but also South Korea, the Philippines, and Australia — should be clearer about their own likely responses to a Chinese attack on Taiwan. These states have the most to lose from a Chinese bid to overturn the status quo. While it is unrealistic to expect regional governments to announce firm commitments to Taiwanese security, it would certainly help the cause of stability in East Asia if they would announce a willingness to impose economic punishments, political sanctions, and increase defense spending in response to an invasion.
For peace to be likely in the Taiwan Strait in the 2020s, Taiwan and its friends will need to take radical action to develop short-term constraints on Chinese action but also look for ways to encourage internal restraint among Chinese decision-makers, something that will require recognizing practically what the Department of Defense has recognized theoretically: that if China comes to view the evolution of the status quo in increasingly negative terms, its incentives not to use force are correspondingly reduced.
Dr. Jared M. McKinney is an assistant professor of international security at the Air War College at Air University, Maxwell Air Force Base, Alabama.
Dr. Peter Harris is an associate professor of political science at Colorado State University and a non-resident fellow with Defense Priorities.
Together, they are the author of Deterrence Gap: Avoiding War in the Taiwan Strait (Strategic Studies Institute, U.S. Army War College, January 2024)
The views expressed are those of the authors alone, and not necessarily those of the U.S. Air Force, Department of Defense, or U.S. government.
Image: People’s Republic of China (Taiwan) Air Force
