A New Nuclear Age

Commentary by Reja Younis

Published August 20, 2024

Vipin Narang, acting assistant secretary of defense for space policy, declared in a speech at the Center for Strategic and International Studies on August 1 that the United States has entered "a new nuclear age." While the administration has historically sought a balance between deterrence and arms control, Narang announced a shift toward "a more competitive approach" reminiscent of the Cold War, with a renewed emphasis on modernizing and expanding the U.S. nuclear arsenal. As Narang announced, "Intermission is over, and we are clearly in the next act."

The Pentagon's new direction appears predicated on at least three core assumptions: coordinated adversarial behavior, the plausibility of limited nuclear employment, and the failure of arms control efforts. While evidence supports these ideas to some degree, none of them should be taken as forgone conclusions. The United States is undoubtedly entering a new era of nuclear competition, but it is still possible to shape the strategic environment. This requires moving beyond a sole focus on military strength and modernization. Instead, a return to first principles, "wedge" strategies to divide adversaries, targeted intelligence gathering, persistent conceptual innovation, and a balanced approach that prioritizes both deterrence and risk reduction is crucial for ensuring long-term U.S. national security.

Nuclear Posture at a Crossroads

In the post-Cold War era, each presidential administration strived to transcend "Cold War thinking," diminish nuclear reliance, and take tangible steps toward disarmament. The Biden administration was no exception. While the 2022 Nuclear Posture Review (NPR) did not take the "sole purpose" policy anticipated by President Joe Biden's campaign, it went so far as to identify "current and planned nuclear capabilities that are no longer required to meet our deterrence needs." This included retiring the B83-1 megaton gravity bomb and cancelling the nuclear sea-launched cruise missile (SLCM-N).

The 2022 NPR concluded that the "SLCM-N was no longer necessary given the deterrence contribution of the W76-2 [nuclear warhead], the uncertainty regarding whether SLCM-N on its own would provide leverage to negotiate arms control limits on Russia's [nonstrategic nuclear weapons], and the estimated cost of SLCM-N in light of other nuclear modernization programs and defense priorities." The NPR did not add nuclear weapons to the U.S. arsenal and delayed the retirement of older systems. Instead, it sought adjustments in the existing force posture; increased integration of conventional and nuclear planning; and reaffirmed a commitment to modernizing U.S. nuclear forces, nuclear command, control, and communications systems (NC3) as well as production and support infrastructure. Essentially, this represented the same nuclear modernization program that had been supported by the previous two administrations.

Since the 2022 NPR, the defense community has intensified its debate over deterrence in the context of multiple nuclear challengers. The central question remains: What capabilities does the United States require to deter its adversaries and assure its allies? In the fall of 2023, the public release of the congressionally mandated bipartisan Strategic Posture Commission (SPC) and the Department of State's International Security Advisory Board (ISAB)-reporting to the undersecretary of state for arms control and international security, Ambassador Bonnie Jenkins-both grappled with nuclear multipolarity. The SPC highlighted the possibility of "opportunistic or collaborative" aggression from China and Russia in the 2027-2035 timeframe. To that end, the SPC recommended nuclear force posture modifications, including the development and deployment of more theater nuclear delivery systems. On October 19, 2023, Jon L. Kyl, vice chair of the SPC, testified to the U.S. Senate Armed Services Committee that the attributes the commission included for such theater capabilities were an endorsement of the controversial SLCM-N program.

To critics at the time, this appeared to be a scenario with low probability but high potential cost for defense planning. Critics also contended that collusion fostered a sort of doomsday mindset and exaggerated the needs of deterrence. The ISAB countered the SPC on this, suggesting that Russia and China might never reach a level of alliance that would necessitate U.S. planning for coordinated attacks. Despite their disagreements, both the ISAB and SPC concurred that, given the costs, the United States need not pursue a strategy that relies on outnumbering aggregate Chinese and Russian nuclear forces to successfully deter them and assure allies and partners.

Growing Threats and Uncertainty

Over the past year, the United States has perceived a growing sense of threat. In his 2023 address delivered at the Arms Control Association's annual conference, National Security Advisor Jake Sullivan stated that the United States was at an "inflection point" due to the absence of cooperation that had typified the post-Cold War era. He acknowledged deep cracks in the post-Cold War nuclear foundation but said there was no need to increase U.S. strategic nuclear arms deployments and offered talks to adversaries "without preconditions."

Earlier this year, National Security Council senior director Pranay Vaddi used the same forum to describe "a more competitive approach" to arms control, outlining a policy shift aimed at pressing Moscow and Beijing to reverse rejections of U.S. calls for arms limitation talks: "Absent a change in the trajectory of adversary arsenals, we may reach a point in the coming years where an increase from current deployed numbers is required." While he reiterated the administration's commitment to international arms control and nonproliferation, he argued that "Russia, the PRC and North Korea are all expanding and diversifying their nuclear arsenals at a breakneck pace-showing little or no interest in arms control."

Like Sullivan's and Vaddi's speeches, Narang emphasized that the United States is adapting its deterrent as a reaction to "revisionist" adversarial behavior, but also that "it would be irresponsible for the United States to not confront and address this new reality." He described the choice adversaries have made to not only reject calls to diplomacy and risk reduction-but to choose conflict and outright competition every time. He cautioned against adversaries continuing down this path with the same deterrent message Vaddi made earlier in the year: "There is no need to grow the stockpile yet, but adjustments to the number of deployed capabilities may be necessary if our adversaries continue down their current paths."

Examining the Assumptions behind DOD Strategy

The Department of Defense (DOD)'s "more competitive approach" is built upon a series of assumptions that require critical and continuous evaluation. A key premise is the possibility of coordinated actions among adversaries elevating the risk of opportunistic aggression. This concern aligns with the recommendations of the SPC. The SPC argued that current U.S. strategy assumes a "one major war" sizing construct for the conventional force. While this strategy might currently deter opportunistic aggression in a two-theater situation, the SPC warned that it will be inadequate by 2027. The commission suggested that insufficient conventional forces would lead to reliance on nuclear weapons to deter or counter opportunistic aggression on a second front.

Narang's emphasis on "simultaneity," "growing collaboration," and "evidence of collusion" reflects a mounting recognition of multi-theater, multi-actor conflict. Regarding North Korea, Narang sounded the alarm not just on the growth of its arsenal and its total rejection of attempts to diplomatically engage with the United States, but also regarding the deepening strategic partnership between North Korea and Russia. This mutual defense agreement, signed two months ago and pledging mutual aid if either country faces "aggression," is likely the strongest connection between Moscow and Pyongyang since the end of the Cold War. Even if the prospect of collaboration may seem remote between these adversaries, it remains a high-consequence outcome that requires planning and potential adjustments.

However, it will be crucial to periodically evaluate collusion and work to alter this "reality foisted on us" (in Narang's words), rather than simply assume its inevitability. While there may be current evidence of China and Russia's growing collaboration-particularly with their recent joint exercise-the two countries share a long and complicated history marked by periods of intense strategic rivalry. They are not natural partners. On the other hand, while alarming, it is not yet clear whether a North Korea-Russia partnership will be strategic in nature, or whether enough trust exists between both countries. It is critical to avoid overestimating the cohesion and durability of these alignments. Alliances can be based on shared interests and adversaries, but they are also based on a shared understanding of history and trust.

What binds NATO, for instance, is not merely shared threats but a shared understanding of the past and a desire to not repeat the mistakes that led to world war. Thus, adversarial collaboration is not comparable to the "asymmetric advantage" offered by U.S. alliances. Narang is correct when he says, referring to the United States, "Our network of allies and partners in the Euro-Atlantic and the Indo-Pacific is an asymmetric strategic advantage that our adversaries can never hope to match." Further, adversaries have an incentive to bluff, as evidenced by Russia's nuclear saber-rattling over Ukraine. The United States cannot afford to play into a bluff, as an arms race could be costly. Narang argues that U.S. adversaries have made choices that have pushed the United States to this posture, but it could still choose to pursue proactive wedge strategies that deny adversaries further collaboration-rather than wait to react after the fact.

The DOD's second key assumption is the possibility of "multiple nuclear challengers" resorting to limited nuclear strikes when on the brink of defeat in a regional conventional crisis. As a result, the DOD is pursuing a "flexible," "smart," and "fitter for purpose" posture. This includes the decision to proceed with the SLCM-N, albeit previewed via inclusion in the National Defense Authorization Act. The decision to pursue the B61-13 was also not on the program of record. Narang reiterated the significance of the triad and NC3 modernization efforts.

Operating under this assumption is crucial for at least four reasons:

1. S. adversaries have been making strides in this area, while the U.S. arsenal has suffered from decades of neglect and delayed modernization.
2. Russia's growing arsenal of lower-yield nuclear weapons, coupled with its coercive nuclear threats, poses a significant challenge. These weapons could be used to escalate conflicts or intimidate Russia's adversaries. Russian strategic writing tends to theorize that low-yield or nonstrategic nuclear weapons can maintain "combat stability" of forces engaged in operation (and even manage escalation, hence making Russia's behavior even riskier). This cannot be left unchecked in a limited nuclear use scenario.
3. This upgrade is one part deterrence and one part assurance for the United States' "asymmetric advantage"-U.S. allies. Assurance comes not only from consultations and dialogues but also from the credibility of the United States' extended deterrent.
4. The department's focus on strategic necessity rather than competitive matching is crucial. It appears that the DOD is not in a "match mindset" where the development of new or matching systems is seen as a test of resolve. Instead, its choices are strategic decisions related to deterrence, war fighting, or assurance.

However, the complexities of this issue extend beyond modernization and upgrading. Deterrence relies on the capability to deliver an effective response to an enemy action, the credibility of threats to follow through with that response, and effective communication of the promised response. Put simply, deterrence relies on the ability to hold at risk what an adversary values to prevent them from taking undesirable actions. While preparing for limited nuclear use can deter use from ever occurring in the first place, there is a mammoth task ahead involving deciphering the "unknowns" surrounding the United States' adversaries-particularly in terms of what they value and where escalation thresholds lie. There is an urgent need to rethink escalation across the ladder, or wormhole, as a result, but there is also a pressing need to communicate U.S. stakes in certain regions and contingencies. Capabilities alone will not be sufficient.

If adversarial decisionmakers perceive that the United States does not have any stakes in a conflict -and relatedly, that the costs would be worthwhile (i.e., based on the perception that the United States would not take nuclear risks in return)-they may be more willing to engage in risky behavior. Conversely, if U.S. policymakers continue to believe that U.S. adversaries have the upper hand in a limited-use scenario, the United States might behave in a more restrained manner. Therefore, clear messaging of U.S. stakes and the expected costs adversaries might incur for risk taking-before a conflict occurs-takes on increased salience. Further, the United States has an imperative to allocate more intellectual capital toward the mastery of nebulous concepts such as intra-war deterrence, escalation management, calibration, and conflict termination.

The DOD's final assumption carries the greatest level of risk. While Narang continually emphasized the United States' commitment to arms control and risk reduction, he also underscored adversarial rejections of these efforts and that arms control requires "willing partners." According to Narang, U.S. policymakers have the responsibility to not only lead by example, but also to understand when such overtures are no longer working in the nation's favor. This kind of rhetoric could inadvertently diminish U.S. leadership on these issues. Arguably, arms control isn't at a dénouement-it's also in its next act. Tailored strategies, behavior-based incentives, and confidence-building measures are essential to create conditions conducive to future diplomacy and cooperation. Deterrence and risk reduction must coexist, preventing either from dominating the nation's strategic approach. This balance is essential for safeguarding U.S. national security in an increasingly uncertain world.

Beyond Modernization: Toward a More Stable Nuclear Future

The United States stands at a critical juncture in its nuclear strategy. The decision to adopt a "more competitive posture," while prudent given the evolving security landscape, requires continuous reassessment. Several recommendations can help accomplish this goal:

1. Avoid the "inevitability trap." The United States should actively work to prevent the solidification of adversarial alliances. This requires a proactive approach, utilizing wedge strategies to exploit potential divisions among adversaries and discourage further collaboration. Meanwhile, the United States should also continue to strengthen the asymmetric advantage provided by U.S. alliances. These relationships offer not just military strength but also a powerful counterweight to potential adversarial coalitions.
2. Prioritize strategic clarity. The United States should prioritize clearly communicating U.S. stakes and red lines to adversaries and international audiences. This includes unambiguous messaging about the potential costs they might incur for engaging in risky behavior. Strategic clarity can also be achieved through increased intelligence efforts on adversarial values and thresholds, thereby enhancing deterrence.
3. Invest in intellectual capital. The United States should also devote greater resources to understanding complex and evolving concepts like intra-war deterrence, escalation management, and conflict termination. Narang's vision of cultivating a new generation of strategic thinkers offers a promising path forward. However, these future leaders must possess a broad-based understanding of nuclear issues, be encouraged to anticipate challenges, and continually question first principles-rather than simply reacting to crises or adversarial actions.
4. Lead in arms control and risk reduction. Even in a competitive environment, the United States should continue to demonstrate leadership in arms control and risk reduction. While adversarial intransigence is frustrating, the United States should continue to propose innovative solutions, improve confidence-building measures, engage in dialogue even when prospects seem dim, and set an example for responsible nuclear behavior. There is often no better time for arms control than right after points of high tension. History offers potential lessons; Reagan's strategic buildup, for instance, may have inadvertently spurred Soviet concessions.

By adopting these recommendations, the United States can navigate the complexities of "a new nuclear age," deter aggression, and contribute to a more stable world. The stakes could not be higher.

Reja Younis is the associate fellow with the Project on Nuclear Issues in the International Security Program at the Center for Strategic and International Studies (CSIS) in Washington, D.C.

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