Deterrence in a two-peer world requires prudence

Washington’s plans to rebuild its nuclear arsenal conceived in the early 2010s assumed a world in which Russia was not an acute threat, China maintained a modest nuclear deterrent, and arms control constrained US and Russian nuclear forces. None of those conditions remain.

Today, China’s extensive nuclear buildup and increasingly assertive foreign policy, Russia’s continued modernization and nuclear saber-rattling, and the erosion of arms control define a new era. These trends are prompting a reexamination of US nuclear strategy not seen since the Cold War’s end. What conflict scenarios must be anticipated? How large and diverse should the arsenal be to deter both Russia and China simultaneously? And can arms control contribute to US security amid deepening tensions?

Washington faces the challenge of preserving credible deterrence and reassuring allies against two potential nuclear peers—possibly acting together—without fueling dangerous instability or draining resources from other defense priorities. This will require a balanced approach: continuing modernization and hedging against uncertainty, while avoiding counterproductive arsenal growth and pursuing arms control to reduce risks.

The new nuclear threat environment 

Nuclear weapons are increasingly salient in international politics. China’s quest to become a world class nuclear power amid rising tensions with the United States is the most striking development. The United States projects China will field about one thousand operational warheads by 2030 and potentially fifteen hundred by 2035—up from roughly two hundred in 2020. Beijing’s construction of hundreds of new intercontinental ballistic missile (ICBM) silos, focus on increasing launch readiness, and pursuit of more flexible response options reflect a posture aimed at enhancing survivability, countering US advantages, and improving its ability to control the escalation of a nuclear conflict.

Russia continues to modernize its forces, broaden the role of nuclear weapons in its doctrine, and use nuclear bullying to deter Western support for Ukraine. Meanwhile, the arms control framework that once bounded the US-Russia nuclear relationship has effectively collapsed. The last pillar of this framework, the 2010 New Strategic Arms Reduction Treaty (New START) expired in February with nothing to replace it.

Longstanding US nuclear strategy has been that credible deterrence of nuclear attack against the US homeland and extended deterrence to US allies and partners requires several elements. These include:

• Maintaining sufficient survivable forces in the event of a large-scale strike on un-alerted US forces;
• Retaining nuclear counterforce capabilities “to reduce potential adversaries’ ability to employ nuclear weapons against the United States and its allies” (aka damage limitation) to the extent practicable if deterrence fails and; 
• Ensuring the availability of graduated response options against potential adversary attempts to escalate out of failed conventional aggression.

The United States previously had to deter only one nuclear peer and could treat China as a lesser threat. Now Washington must prepare to face Russia and a far more formidable nuclear China. Russian and China could even coordinate, or one could act opportunistically while the United States is engaged with the other.

Some former government officials and experts warn this shift presents fundamentally new challenges. Ignoring the challenges would leave Washington and its allies vulnerable and would signal waning resolve. The bipartisan Congressional Strategic Posture Commission concluded in its October 2023 report that the current US nuclear modernization program is inadequate. It recommended urgent preparations to upload reserve warheads after New START’s expiration, develop additional limited‑use options, and plan for a larger force in the longer term. 

The Biden administration acknowledged that deterring multiple nuclear adversaries might soon require a bigger and more diverse deployed arsenal, but deferred any decision to the Trump administration. Whether the Trump administration will revise US force requirements to address China’s nuclear transformation remains to be seen. The administration’s National Defense Strategy, released in January, stated: “We will modernize and adapt our nuclear forces accordingly with focused attention on deterrence and escalation management amidst the changing global nuclear landscape.”

Nuclear force sizing considerations  

Strategic forces

China is the primary driver of the concern that the current US arsenal—1,550 deployed warheads and seven hundred deployed delivery systems—is insufficient, particularly Beijing’s recent construction of more than 300 new silo-based ICBMs. Advocates of increasing the deployed arsenal to hold these targets at risk argue that doing so is necessary to fulfill US nuclear employment objectives, including the damage limitation objective, against both Russia and China simultaneously.

These advocates are correct that there is nothing magical or sacrosanct about 1,550 warheads and that New START was negotiated in a world that has changed markedly over the past fifteen years. Yet other considerations are relevant to the question of whether an increase is needed.

First, analysis conducted during President Barack Obama’s second term concluded that core US targeting objectives could still be satisfied with roughly one‑third fewer deployed weapons than New START allowed. If the US arsenal is more than enough for deterrence against Russia, that suggests some available headroom to address growth in China’s force, at least in the near term.

Second, if a US decision to grow the deployed force triggers offsetting responses from Russia and China, that could erase any relative advantage Washington might have gained from an increase.

A third consideration is why an increase is necessary on a day-to-day peacetime basis, as the deployed force can be generated and uploaded to higher levels in a crisis or escalating war. (A counter to this argument would be that there might not be enough lead time to upload in these scenarios.) Moreover, excessive uploading of warheads could reduce the operational flexibility of the arsenal.

Even if growth isn’t required in the near term, a point might come when it could be necessary if China builds up its warheads and launchers to the high end of current projections—or beyond them. But if Beijing levels off at one thousand warheads, the case for holding steady would be stronger.

Geopolitical risk is not the only challenge facing the US nuclear enterprise. Practical constraints loom large. The ongoing modernization program will yield fewer delivery systems on submarines than today’s arsenal, as the new Columbia‑class ballistic missile submarines (SSBNs) will carry eight fewer missile tubes than their Ohio-class predecessors. The program also faces mounting cost overruns, schedule delays, and performance issues, which could force difficult trade‑offs with conventional modernization priorities.

Near‑term options to expand US strategic forces are limited to reactivating four missile tubes per Ohio‑class SSBN deactivated under New START and uploading additional warheads to deployed delivery systems from the reserve stockpile. New delivery systems beyond existing modernization plans cannot begin to be fielded until the mid- to late-2030s, and their acquisition would further increase costs, depending on the scale of expansion. (Modification of some existing systems to make them more capable could potentially be achieved sooner.)

The confluence of the above geopolitical and modernization transition risks means any uploading to address one of the risks would reduce the ability to address the other—as well as any unforeseen technical problems affecting the functioning of a type of delivery system or warhead, or any operational risk caused by advances in adversary capabilities.

Nonstrategic forces

There is also a debate about whether US nonstrategic nuclear capabilities are sufficient in a two‑peer environment. One argument is that Russia and China believe their theater nuclear forces provide coercive leverage and escalation management options that Washington’s lower-yield air‑ and sea‑based weapons cannot match. (The United States fields a small number of B61 nuclear gravity bombs in Europe but has not housed dedicated theater nuclear forces in the Indo-Pacific since the end of the Cold War.) Some allies also worry this asymmetry could undermine US resolve and capacity to defend them. 

Russia’s excessive reliance on nonstrategic nuclear weapons (it is believed to possess one to two thousand such weapons) seems to be driven by its perception of a conventional imbalance vis-à-vis the United States and NATO more broadly. According to the 2025 US intelligence community’s annual threat assessment, “Russia’s vast arsenal of nonstrategic nuclear weapons helps it to offset Western conventional superiority and provide formidable escalation management options in theater war scenarios.” The Defense Intelligence Agency added that “Russia almost certainly seeks to avoid direct conflict with NATO because it assesses it cannot win a conventional military confrontation with the alliance.”

New US theater capabilities with different military characteristics—such as a new sea-launched nuclear-armed cruise missile—would give the president additional options to respond to limited Russian nuclear use. But if Russia’s theater weapons are intended to counter NATO conventional superiority, it’s not clear that additional US theater capabilities would have a significant impact on Russia’s threshold for nuclear use beyond existing US and Alliance options. According to Michael Kofman and Anya Loukianov Fink, two experts on Russian nuclear strategy: “One of the misperceptions about Russian nuclear strategy is that it takes advantage of lower-yield nuclear weapons that the United States does not have. This appears nowhere in Russian military writings or deliberations.” Meanwhile, the best way to deter Russian limited nuclear use is to perpetuate Russia’s perception that a conventional war with NATO would be unwinnable for Moscow so that it doesn’t start such a war in the first place.  

The Defense Intelligence Agency assesses, “China probably seeks lower-yield nuclear warhead capabilities to provide proportional response options that its high-yield warheads cannot deliver” for its theater-range delivery systems such as the DF-26 missile. A dedicated regional nuclear capability in the Pacific would give Washington a response option it doesn’t currently have. Yet whether China is pursuing low-yield options to gain a coercive edge over the United States in a conventional conflict or to offset perceived US advantages in nonstrategic arms remains uncertain. The answer matters for determining the degree to which a dedicated US option would strengthen deterrence.

Any potential benefits of extra US nonstrategic weapons should be weighed against the potential risks. These hazards include the unintended escalation risks of adding nuclear options to existing or planned conventional ground- and sea-launched missiles (adversaries could assume any dual-capable missile launch as nuclear) and reduced availability of launchers to fire conventional weapons. 

An additional consideration is that Washington might face conventional inferiority in one theater in a multi‑peer conflict, forcing it to consider increased reliance on nonstrategic nuclear options for war fighting. But US first use would carry high escalation risks and could require scores—if not hundreds—of additional warheads, a number likely beyond the near‑term capacity of the US nuclear production base.

Key questions

Where one falls on the sufficiency question depends greatly on what conflict scenarios the United States and its allies need to be prepared to deter and respond to, as well as the associated nuclear employment objectives, posture, and force structure one believes is required for deterrence in these scenarios. Reasonable people can disagree on these determinations and how much risk is prudent to accept given competing priorities. 

As the Trump administration grapples with the “how much is enough” question, additional analysis would be beneficial for identifying the available option space in the new strategic landscape. Key questions include the following. 

• Does the United States need to achieve a similar level of damage limitation against multiple adversaries simultaneously? Or would the ability to limit damage from one adversary while inflicting a lesser, though still intolerable, level of damage on the second adversary be sufficient? 
• Do Russia and China perceive gaps in US nuclear capabilities at both the strategic and regional or theater levels?
• How would augmented strategic nuclear capabilities—alongside improved long-range conventional strike and missile defenses—be expected to enhance deterrence, and what potential adversary responses and stability implications should be considered? 
• What are the potential benefits and risks of additional dedicated US theater nuclear capabilities for shaping adversary decision-making during crisis and conflict, and how might they affect escalation dynamics, intra-war deterrence, and conflict termination?
• What are the current and future geopolitical, transition, and operational risks the nuclear enterprise needs to hedge against? What are the options to mitigate them?
• Are there nonnuclear alternatives that could meet deterrence objectives, especially considering rapid advances in technology? 

Arms control considerations

After returning to office, President Donald Trump wasted little time in calling for negotiations with Russia and China to “denuclearize . . . in a very big way.” 

A year later, the president decided not to accept or counter Russian President Vladimir Putin’s offer to continue observing the New START limits for one year beyond the treaty’s expiration. Instead, senior administration officials have doubled down on the need to pursue multilateral arms control that includes additional types of nuclear weapons and both Russia and China.

Russia has indicated it will continue to observe the treaty’s central limits on warheads and delivery systems so long as the United States does. Given there is no immediate need for the United States to expand the deployed arsenal—and even if there were, uploading would take time—the Trump administration should not give Russia a reason to build up. At the same time, the administration should push for the resumption of a dialogue on strategic stability, risk reduction, and a successor agreement to New START. The discussions should address strategic and nonstrategic weapons not captured by New START.

Such steps would preserve at least informal limits on Russia’s strategic forces while Washington reviews requirements to address China, restore communication on nuclear issues, and increase diplomatic pressure on Beijing. In addition, this approach would be consistent with the National Security Strategy’s call to “reestablish strategic stability with Russa.” 

As the administration pursues its goals for arms control in the new security landscape, it is important to remember that arms control is a tool and not an end in and of itself. It is a means to manage competition and enhance US competitive advantages. And it is a tool that retains considerable value. 

There is value in verifiable weapon ceilings, transparency about weapon holdings, counteracting the potential peril of emerging technology, and addressing particularly destabilizing types of weapons such as the placement of strategic weapons in space. There is value given the limitations on the US ability to keep up in a nuclear competition, due to the constraints on its ability to build new weapons. And there is value in demonstrating US leadership and exercising the skills of a waning US arms control enterprise.

Some analysts assert a nuclear buildup would create leverage for future negotiations. But US-Russian arms control history suggests a more complicated story. Building new strategic systems beyond current plans isn’t possible for another decade and thus offers no near‑term bargaining value. Whether uploading reserve warheads would influence Moscow or Beijing depends on how they factor these warheads into their threat assessment. Decades of US nuclear superiority did not persuade Beijing to negotiate, and Russia conditions discussions of its exotic strategic delivery systems (e.g. Skyfall and Poseidon) and nonstrategic weapons on limits to US missile defenses and advanced conventional strike capabilities.

It remains to be seen if meaningful progress on arms control is possible so long as Russia’s aggression against Ukraine and China’s unwillingness to get off the arms control sidelines continues. But if a process does get underway, several issues will likely arise.

If the Trump administration is open to another bilateral accord on US and Russian strategic forces, what the administration proposes to Moscow is likely to be influenced by an assessment of what is needed to deter China. That assessment could yield a proposal to Moscow with higher limits on deployed strategic weapons than New START, as well as a shorter duration, to hedge against uncertainty over China’s buildup. This would reverse the trend of progressively lower limits in previous agreements. But that does not mean there wouldn’t be value in such an arrangement in terms of stability, predictability, and transparency, especially compared to an alternative with no agreement. (Such an agreement also wouldn’t require the United States to operate at the height of those limits on a day-to-day basis.) 

Missile defense will inevitably feature in any negotiation, especially one seeking limits below or beyond New START. Trump’s interest in enhancing US homeland defenses via Golden Dome has prompted unsurprising criticism in Moscow and Beijing, but pursuing arms control need not be in conflict with missile defense. Workable compromises exist if both sides are willing to bargain. Washington can both augment its missile defenses and use them as a lever for securing significant Russian and Chinese concessions.

Non‑strategic nuclear weapons are often viewed as essential to any New START successor. But as Michael Albertson of the Center for Global Security Research notes, the Trump administration should weigh potential benefits against complexity and cost. Given US concerns about Russia’s potential limited use of nuclear weapons if it is losing a conventional war, even cutting Russia’s nonstrategic arsenal in half would not resolve the issue. Greater value could come from data exchanges, notifications, on‑site inspections, and consolidating storage sites.

It remains unrealistic to expect China to immediately join a trilateral agreement with the United States and Russia that limits nuclear weapons. A more achievable near-term approach is to begin a bilateral conversation on risk reduction topics such as crisis management and guardrails at the intersection of emerging technology and nuclear risk, which could later be broadened to a multilateral conversation. If momentum can be generated, seeking a better understanding of China’s arsenal composition and plans should be a high priority. If the United States knew, for example, that China had an end point in mind for its buildup, that would provide much-needed confidence and predictability and help to avoid worst-case planning. 

Conclusion

The US response to the new strategic environment must be based on more than just a reconsideration of numbers and types of nuclear weapons. By aligning prudent military planning with purposeful diplomacy, the United States can preserve deterrence, prevent dangerous competition, and strengthen the foundations of global security in an era of unprecedented nuclear complexity.

This issue brief is part of the Scowcroft Center for Strategy and Security’s Great nuclear debate series, a curated anthology of perspectives on arms control, force sizing, and missile defense from leading experts.

Kingston Reif is a senior international and defense researcher at RAND. From 2021 to 2024, he served as the deputy assistant secretary of defense for threat reduction and arms control. 

Forward Defense leads the Atlantic Council’s US and global defense programming, developing actionable recommendations for the United States and its allies and partners to compete, innovate, and navigate the rapidly evolving character of warfare. Through its work on US defense policy and force design, the military applications of advanced technology, space security, strategic deterrence, and defense industrial revitalization, it informs the strategies, policies, and capabilities that the United States will need to deter, and, if necessary, prevail in major-power conflict.

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Image: An unarmed Trident II D5 Life Extension missile launches from an Ohio-class ballistic missile submarine off the coast of Florida in September 2025. The four launches were part of a planned test event conducted to evaluate and ensure the continued reliability and accuracy of the system. Photo by US Navy