By Adam Mount
For the first time since the collapse of the Soviet Union, U.S. nuclear strategy is at a crossroads.
The rapid expansion of China’s nuclear forces calls into question fundamental assumptions about how the United States can deter nuclear-armed adversaries. In this context, Congress appointed a bipartisan commission of 12 former government officials to assess the threat environment and make recommendations on the nation’s strategic posture. The final report of the Congressional Commission on the Strategic Posture of the United States, released in October, marks the start of an inchoate debate about how to respond to China’s buildup, the outcome of which will shape the U.S. nuclear arsenal for decades.
Although Biden administration officials clearly have articulated the challenge presented by China’s buildup, the 2022 Nuclear Posture Review presented a strategy to meet it.1 The commission’s report is the first attempt by an entity of the U.S. government to propose an answer to the problem of tripolar deterrence, defined by the former commander of U.S. Strategic Command as the need to deter “two nuclear-capable, strategic peer adversaries at the same time,”2 namely China and Russia. The Pentagon estimates that China’s deployed nuclear warheads have more than doubled since 2020, from 200 to 500, and projects them to more than double again by 2030.3 This increase, combined with expansions in Russian and North Korean nuclear forces, could double the number of nuclear weapons that U.S. forces are ordered to deter by 2035. The challenge is complicated by the need to deter what the commission calls “opportunistic or collaborative two-theater aggression.”
The problem of tripolar deterrence is far more complex than simple arithmetic. China’s buildup and the U.S. response pose significant risks to strategic stability, increasing the chance that adversaries could aggress against U.S. allies, that regional crises could advertently or inadvertently escalate to the nuclear level, and that limited nuclear use could expand into a strategic exchange. All other things being equal, a constant U.S. nuclear force cannot maintain the same strategy and hold twice the number of targets as it does now. Yet, U.S. strategy and other elements of the strategic posture do not need to be held constant. Developing a strategy to maintain strategic stability will require planners to assess a wide range of options, many of which present their own stability risks, fiscal or logistical challenges, or political problems when presented to U.S. allies and partners.
A Strategic Stability Strategy
One set of variables comprises nuclear posture: the numbers, types, positions, and alert status of U.S. nuclear forces. A strategy that depends solely on adjusting nuclear posture may ultimately succeed in holding the additional targets at risk, but may end up being unnecessarily slow or costly, may not help to deter other kinds of threats, or may inadvertently degrade strategic stability. A symmetrical response to China’s buildup is not necessarily the best response.
Many other variables could comprise critical parts of a strategy to maintain stability in the context of tripolar deterrence. For example, U.S. officials may consider how advanced conventional forces could help deter and respond to limited nuclear use in regional conflicts or affect a strategic exchange. Consistent with the Biden administration’s concept of “integrated deterrence,” officials may also seek to develop ways of imposing costs on an adversary by coordinating with allied nuclear or conventional forces or by using space, cyber-, economic, diplomatic, informational, or clandestine means to deny gains or impose costs.4 In many cases, non-nuclear options may be more flexible, credible, and less costly ways of producing the effects necessary to deter an attack.
In developing a strategy for tripolar deterrence, the U.S. president could also choose to adjust a range of parameters that structure nuclear planning, including the categories of assets that nuclear forces would target in specific contingencies, the quantity of damage required at different times after an enemy launches a strategic attack, the damage expectancy requirements attached to specific weapons systems against specific targets, or the level of risk they are willing to accept that a technological development could suddenly render a leg of the triad vulnerable. The president also may opt to issue updated guidance about how much risk he is willing to accept that an adversary could carry out a surprise disarming strategic attack or comes to doubt the credibility of available U.S. options for responding to limited nuclear use. Adjusting any of these parameters could change requirements for the number of U.S. weapons required to deter the growing arsenals of adversaries. Presidents customarily do not issue direct guidance on these kinds of specific parameters to affect nuclear planning, but they may have to do so if they intend to implement a deliberate strategy for tripolar deterrence.5
The first step toward a deliberate strategy of trilateral deterrence would be to reexamine, at a fundamental level, the purpose of U.S. nuclear weapons. The primary mission that determines the size and structure of U.S. strategic forces is to limit damage to the state and its allies should deterrence fail. A preemptive counterforce strategy, which depends on striking an adversary’s nuclear force before it is launched, is difficult to imagine for several reasons, not least of which is that, even in the best of circumstances, such a scenario would expose the U.S. homeland to several dozen nuclear attacks. A retaliatory counterforce strategy is equally problematic because, even in the best of circumstances, it would represent an attempt to limit damage after a catastrophic attack has already occurred. Any complete strategy for tripolar deterrence begins with answering these basic questions: Is damage limitation the primary mission of U.S. forces and, if so, how much damage and in what circumstances?
Confronting these complex questions, the commission reached a simple answer: an across-the-board buildup of U.S. nuclear forces. Its report recommends pursuing increases in the size, diversity, and alert status of every nuclear system, including multiple warheads and road-mobile options for new intercontinental missiles, more cruise missiles, more bombers postured on continuous alert with more tankers to support them, more submarines, more capability to penetrate adversary air and missile defenses, and demanding requirements for new theater nuclear options to attempt to control escalations.
Despite evidence that development on homeland missile defense interceptors has stalled, the report recommends investing heavily in new programs and expanding their mission set beyond North Korea to include an ill-defined category of coercive attacks from Russia and China.6 Collectively, the proposals would reverse decades of initiatives from presidents of both parties to reduce reliance on nuclear weapons in favor of non-nuclear options that they considered more flexible. For the commission, tripolar deterrence is not a complex strategic problem but simply a deficit of nuclear weapons. Its answer to an arms race is an arms race.
The Commission’s Solution
The commission’s solution to the problem of tripolar deterrence is not a strategy. The report makes no attempt to specify the categories or numbers of targets that it believes must be held at risk and so does not provide estimates of how many additional systems to procure, when they will be required, or which to prioritize. The report rightly identifies a need to “deter or counter opportunistic or collaborative aggression” in multiple theaters, but it does not describe what this might look like or how it would affect U.S. plans and force requirements.7 Most importantly, the commission does not consider the significant risk that increases in U.S. nuclear forces could degrade crisis stability, thus increasing the risk of nuclear use. It is an arithmetic approach to the problem without the arithmetic.
Because it does not articulate its assumptions about what is required to deter U.S. adversaries, the report cannot explain why the commission believes current U.S. forces would be insufficient to inflict the required effects in relevant contingencies, the number of systems that would be required, or how a buildup in U.S. forces could meet their objectives given the likelihood that China and Russia would respond with further increases in their forces.8 The commission’s chapter on strategy states that “the basis for U.S. nuclear strategy is assured second strike,” but this standard cannot guide policy without an explanation of what they believe would constitute “unacceptable damage.”9 Adjustments to U.S. nuclear force structure could be part of a solution to the “two-peer problem,” but it is not a solution to suggest doubling the size of the U.S. arsenal without justifying the figure, as one commissioner did.10
The commission report also does not account for the major fiscal, logistical, and political constraints that would inhibit implementation of its recommendations. It acknowledges that its proposals “will drive extraordinary demands on the already-constrained” departments that manage the arsenal, but makes no attempt to offer recommendations that work within those constraints or realistic measures to loosen them.11 Instead, the report recommends a vast “overhaul and expansion of the capacity of the U.S. nuclear weapons defense industrial base” and the U.S. Department of Energy/National Nuclear Security Administration nuclear security enterprise and offers proposals that range from constructive to semantic to quixotic.12 Even if all of these specific steps were implemented, it is difficult to see how they add up to the enormous increase in capacity that would be required to enact the commission’s expanded force structure.
In practice, the commission’s answer to the two-peer problem will be far more influential on the gathering debate on the future of nuclear strategy than it is on actual U.S. policy. Because of the standing of the commission’s members and the political appeal of their findings, the commission’s answer likely will be accepted in many quarters as the default position. As the debate becomes detached from realistic options, it increases the risk that the United States never develops a coherent approach to the strategic challenge it faces.
The report should prompt a national debate on a strategy for tripolar deterrence. At present, no group has presented a viable alternative to a major expansion of the U.S. nuclear arsenal and its supporting infrastructure. In one recent article, three experts propose shifting away from targeting opposing warheads to targeting civilian infrastructure, which could be accomplished with relatively fewer warheads.13 This proposal is far out of step with the U.S. commitment to adhere to the law of armed conflict and so is unlikely to influence policy. By giving voice to the strawman constructed by advocates of a buildup, calls for countervalue targeting also does not help to promote a realistic debate on how to respond to the tripolar challenge.14 It may well be the case that an effective strategy for tripolar deterrence abandons any requirement for preemptive counterforce and accepts that assured second strike can be accomplished with a relatively smaller force, but the strategy must conform to the law of armed conflict to be implemented.
An effective strategy on tripolar deterrence will fall within the broad region between an infeasible buildup and an infeasible shift to civilian targeting. Developing that strategy will require reexamining some of the fundamental assumptions of U.S. nuclear strategy, including the value of damage limitation.
A constructive debate would consider not only the numbers and types of nuclear weapons in the U.S. arsenal, but it would explore how a broad set of variables can interact to enhance deterrence, ranging from the intricate parameters that guide nuclear planning to instruments in other domains of conflict.
Compelling recommendations will account for the significant and foreseeable constraints on U.S. options and the expected responses of adversaries. Most importantly, as the United States reevaluates its strategic deterrence posture, it should remember that its objective is to maintain strategy stability and reject policies that would degrade it.
1. Jake Sullivan, Remarks at the Arms Control Association Annual Forum, Washington, June 2, 2023, https://www.whitehouse.gov/briefing-room/speeches-remarks/2023/06/02/remarks-by-national-security-advisor-jake-sullivan-for-the-arms-control-association-aca-annual-forum/.
2. Aaron Mehta, “STRATCOM Chief Warns of Chinese ‘Strategic Breakout,’” Breaking Defense, August 12, 2021, https://breakingdefense.sites.breakingmedia.com/2021/08/stratcom-chief-warns-of-chinese-strategic-breakout/.
3. U.S. Department of Defense, “Military and Security Developments Involving the People’s Republic of China 2023: Annual Report to Congress,” October 19, 2023, https://media.defense.gov/2023/Oct/19/2003323409/-1/-1/1/2023-MILITARY-AND-SECURITY-DEVELOPMENTS-INVOLVING-THE-PEOPLES-REPUBLIC-OF-CHINA.PDF.
4. Stacie L. Pettyjohn and Becca Wasser, “No I in Team: Integrated Deterrence With Allies and Partners,” Center for a New American Security, December 2022, https://s3.us-east-1.amazonaws.com/files.cnas.org
/documents/IntegratedDeterrence_Final-1.pdf; Adam Mount and Pranay Vaddi, “An Integrated Approach to Deterrence Posture,” Federation of American Scientists, n.d., https://fas.org/wp-content/uploads/2021/01/An-Integrated-Approach-to-Deterrence-Posture.pdf.
5. Sharon K. Weiner, “Resetting the Requirements for Nuclear Deterrence,” Arms Control Today, Vol. 52, No. 1 (2022): 12-16; Adam Mount, “The Biden Nuclear Posture Review: Obstacles to Reducing Reliance on Nuclear Weapons,” Arms Control Today, Vol. 52, No. 1 (2022): 6-11.
6. Congressional Commission on the Strategic Posture of the United States, “America’s Strategic Posture,” October 2023, p. 63, https://armedservices.house.gov/sites/republicans.armedservices.house.gov/files/Strategic-Posture-Committee-Report-Final.pdf.
7. Ibid., p. 31. See Keith B. Payne and David J. Trachtenberg, “Deterrence in the Emerging Threat Environment: What Is Different and Why It Matters,” Journal of Policy & Strategy, Vol. 2, No. 4 (2022): 3-51.
8. For a more modest, specific, and attainable response with a broadly similar approach to the commission, see Center for Global Security Research Study Group, “China’s Emergence as a Second Nuclear Peer: Implications for U.S. Nuclear Deterrence Strategy,” Lawrence Livermore National Laboratory, 2023.
13. Charles L. Glaser, James M. Acton, and Steve Fetter, “The U.S. Nuclear Arsenal Can Deter Both China and Russia,” Foreign Affairs, October 5, 2023, https://www.foreignaffairs.com/united-states/us-nuclear-arsenal-can-deter-both-china-and-russia.
14. Keith B. Payne et al., “The Rejection of Intentional Population Targeting for ‘Tripolar’ Deterrence,” National Institute for Public Policy Information Series, No. 563 (September 26, 2023), https://nipp.org/wp-content/uploads/2023/09/IS-563.pdf.