The role of nuclear weapons in a Taiwan crisis

Gregory Weaver

Source Link

Executive summary

The potential for a conflict over Taiwan is increasing due to China’s nuclear and conventional military buildup and the threat of two simultaneous conflicts with China and Russia, which would severely stress the ability of US and allied conventional forces to win in both theaters. Nuclear weapons will cast a long shadow over a Taiwan conflict and could play multiple roles in the deterrence and warfighting strategies and operations of both the United States and the People’s Republic of China (PRC). A conflict over Taiwan has a number of attributes that will shape those roles. Those attributes make the potential for limited nuclear escalation real and uncontrolled nuclear escalation possible.

In order to prevent war and escalation in war, US policymakers and military planners must take the role of nuclear weapons in a Taiwan conflict seriously. The United States should communicate four focused deterrent messages to China and reassure its allies and partners that it can deter Chinese nuclear use. The United States should reevaluate its theater nuclear capability requirements for a Taiwan conflict and carefully analyze options to defeat a Chinese amphibious invasion of Taiwan with limited nuclear strikes if necessary. Finally, the United States must credibly address the potential for collaborative or opportunistic aggression by China and Russia in an environment in which both are peer nuclear adversaries. This requires determining what the US strategy should be to address the two-peer threat, optimizing US and allied conventional forces to address it, and reshaping US nuclear capabilities if necessary. The United States needs to know now whether it is going to require a nuclear force that is larger, or different, or both, because changing the current modernization program requires immediate action to address the threats in time.

Background

The political-military competition between the United States and the PRC continues to intensify. The United States Department of Defense (DOD) characterizes China as its “pacing threat,” and is prioritizing conventional force modernization designed to counter the PRC’s rapid and sustained nonnuclear military buildup.1

While the PRC seeks to increase its influence globally and a US-China conflict could erupt over a number of issues, the most likely flashpoint for an armed conflict between the two nuclear-armed major powers is Taiwan. The PRC maintains that Taiwan is a part of China and reserves the right to use military force to seize control of Taiwan if necessary. The United States agrees there is “one China” but opposes Chinese use of force to resolve the status of Taiwan. US policy remains ambiguous about whether the United States would intervene to defend Taiwan should China attack. But a successful Chinese invasion of Taiwan would fundamentally undermine the strategic position of the United States in East Asia by damaging the rules-based international order, causing severe economic disruption (e.g., in the semiconductor industry), and raising questions about the ability and will of the United States to defend its interests, and the interests of its allies.

This political-military status quo has persisted for decades, in part because China has not possessed the military capability to seize Taiwan if the United States (and possibly some if its allies) were to intervene militarily. However, in a February 2023 television interview, CIA Director William Burns noted that PRC President Xi Jinping has directed the Chinese military to be prepared to invade Taiwan by 2027 (emphasis added).2 In addition to the ongoing conventional force modernization and expansion necessary to achieve this goal, China is engaged in the largest nuclear force buildup any country has pursued since the Cold War. The 2021 DOD report to Congress on Chinese military power estimated the PRC may field up to seven hundred nuclear warheads by 2027, and that PRC leadership intends to have at least one thousand warheads by 2030.3 The 2022 version of the report added assessments that China’s current warhead total has roughly doubled, surpassing four hundred, and that the PRC will likely field fifteen hundred warheads by 2035 if the pace of its nuclear modernization continues.“4 Current US nuclear modernization plans envision no significant increase in US nuclear forces over this period, but a debate has begun over whether facing two nuclear peer adversaries for the first time in the nuclear age necessitates an increase in US nuclear forces and/or a change in their composition.

The ongoing shift in the military balance of the conventional and nuclear forces relevant to an armed conflict over Taiwan arguably makes a Chinese decision to resolve the Taiwan problem by force more likely. And that is a problem for both the United States and China.

The problem

The problem the increasing Chinese threat to Taiwan poses to both the United States and China is the prospect of a high-intensity conventional war with a nuclear-armed power over what both sides perceive to be very high stakes. Such a conflict would be very costly even if it remained nonnuclear. But a US-China war over Taiwan also poses the threat of escalation to nuclear weapon use, which would dramatically increase costs if the war remained limited, and pose a potential existential threat to both countries if it does not.

A war over Taiwan poses multilevel deterrence and warfighting problems in both Washington and Beijing.

Deterrence of Chinese conventional aggression against Taiwan requires more than conventional deterrence alone. It also requires intrawar deterrence of PRC limited nuclear escalation, and it may, under some circumstances, require a credible threat to use nuclear weapons first to counter Chinese conventional superiority.

Chinese deterrence of US intervention in a Taiwan conflict also requires more than conventional deterrence. It involves convincing Washington that the conflict might escalate to levels of violence that exceed the importance of the US stake in Taiwan, therefore deterring Washington from intervening in the first place. And it requires intrawar deterrence of US nuclear escalation to defeat the invasion.

A DF-31 missile displayed in 2017. China’s rapid nuclear buildup has included all three legs of its nascent nuclear triad, including land-mobile missiles like the DF-31. Source: Wikimedia/Tyg728

Both sides must also address the warfighting implications of a failure of nuclear deterrence.

Given these multiple ways in which the nuclear forces of both sides could affect the outcome of a Taiwan conflict, US policymakers, strategists, and military planners must take into account the effects the interaction of those nuclear forces would have on US efforts to prevent war and escalation in war, and to secure an outcome favorable to the United States and its allies and partners.

Before analyzing the role of nuclear weapons in Chinese and US strategy and operations in a crisis or conflict over Taiwan, it is important to provide context by outlining the key features of the Taiwan invasion scenario.

Key features of the Taiwan invasion scenario

This analysis focuses on a relatively near-term Taiwan invasion scenario circa 2027.5 That scenario was selected as the baseline because, while China could choose less violent means of seeking to coerce Taiwan to capitulate (a blockade, an air/missile strike campaign, etc.), it is the invasion scenario that would result in the largest-scale conventional conflict and would create the highest stakes for both sides, thus triggering the greatest potential for nuclear escalation. The scenario also matches President Xi’s directive to his military to be ready to invade Taiwan by 2027.

There are eight key features of this scenario that affect the roles both sides’ nuclear forces might play during a crisis and conflict:A Taiwan invasion would be unprecedented: a high-intensity armed conflict between two nuclear-armed major powers. The leaders of both sides would face challenges to nuclear deterrence that no one has faced before.

Each side’s stake in the outcome of such a conflict would be very high. A Chinese defeat could pose an existential internal political threat to the Chinese Communist Party (CCP) and result in Taiwanese independence. A US and allied defeat could undermine US-led alliances in Asia and Europe, and fundamentally undermine the US and allied strategic position in Asia. Chinese occupation of Taiwan would transform that island from a geographic constraint on China’s military operations to a platform from which to project power further. And the incorporation of Taiwan’s economic capacity would further strengthen the PRC.

Both sides would try to deter the other prewar and intrawar. The United States would seek first to deter the invasion and then Chinese nuclear escalation if China were losing in the conflict. China would seek first to deter US and allied intervention in the conflict, and then US nuclear escalation if China was winning.

The conflict would be fought on a scale and with an intensity that would severely test both Chinese and US, allied, and partner conventional forces, potentially to the breaking point. That scale and intensity would mean either side might consider the limited use of nuclear weapons to secure victory or prevent defeat.

Both sides have escalation options short of nuclear weapons use that create potentially decisive strategic level dilemmas for the other. China has space and cyber options that could degrade US power projection. Chinese leadership also might be able to prompt Russian (or North Korean) opportunistic or collaborative aggression, stressing the US military’s ability to fight two major conflicts against nuclear-armed adversaries simultaneously. The Chinese invasion of Taiwan could be the first or second of those conflicts to initiate (i.e., the Taiwan invasion itself could take the form of opportunistic aggression). Those scenarios pose very different challenges to US strategy and forces. The United States and its allies have space and cyber options to degrade Chinese conventional operations, plus the option to blockade shipping to and from China outside the reach of China’s navy and air force. These nonnuclear escalation options raise the prospect of nuclear escalation in response.

The conflict could become protracted if China fails in its initial effort to seize Taiwan but refuses to terminate the conflict. The prospect of a protracted conflict could prompt either side to consider nuclear escalation to bring the conflict to a favorable or acceptable conclusion should either party determine that a protracted war is not in its interest.

By 2027, China’s nuclear force will likely have grown to approximately seven hundred deployed warheads, most of them capable of ranging the United States, giving it a more secure second strike against the US homeland and significant new theater nuclear strike options. While not yet a quantitative “peer” in 2027, a nuclear force of this size is a far greater threat than what the United States faced just a year or two ago.

Finally, perhaps the most defining operational feature of the Taiwan invasion scenario is that it requires the Chinese military to conduct an opposed amphibious and airborne assault across 80-125 nautical miles of ocean onto an island with a population of 23.5 million people, approximately 170,000 active-duty military, and nearly 1.6 million reservists. This is a daunting prospect for China, especially in the face of US and allied military intervention. Current US joint doctrine for amphibious operations states: “The assault is the most difficult type of amphibious operation and one of the most difficult of all military operations due to its complexity” (emphasis added).6 Similarly, the 2022 DOD China military power report notes: “Large scale amphibious invasion is one of the most complicated and difficult military operations, requiring air and maritime superiority, the rapid buildup and sustainment of supplies onshore, and uninterrupted support.”7

These key features of the Taiwan invasion scenario circa 2027 impact both the roles nuclear forces play in Chinese and US strategy and operations and the nature of the nuclear forces needed to fulfill those roles with high confidence.