Maintaining America’s Nuclear Deterrent

Editor’s note: Don’t miss our comprehensive guide to Russia’s war against Ukraine. 

The ongoing Russian invasion of Ukraine and Vladimir Putin’s recent nuclear threats against his neighbors are drawing renewed attention to the critical importance of nuclear weapons. Putin’s recent threats, while outrageous, are only the latest indicator that nuclear danger is increasing. China is expanding its missile forces and threatening its neighbors with nuclear attack, North Korea is testing ever more powerful missiles, and Iran is inching closer to nuclear weapons. Even traditional American security partners like Japan and South Korea are considering independent nuclear forces. Putin’s invasion and subsequent nuclear threats continue an ominous global trend towards strategic competition and nuclear brinksmanship among the great powers.

Against this backdrop, the Biden administration is preparing to issue its Nuclear Posture Review, a critical planning document that lays out priorities for American nuclear forces. Russia’s invasion of Ukraine demonstrates the tremendous importance of getting nuclear-weapons issues right. Russia, China, and other hostile powers threaten America’s allies and interests across the globe. America’s nuclear arsenal will play a critical role in helping the country stand with its partners to deter aggression in the future.

The United States must avoid provoking adversaries unnecessarily. Yet many current policy proposals designed to reduce the chances of inadvertent nuclear escalation would also undermine faith in American nuclear deterrence, making major conventional and nuclear conflict more likely. Deterrence and crisis management can only proceed in tandem. The new Nuclear Posture Review should therefore eschew guidance that would weaken deterrence, and instead commit to stability in declaratory policy, continued force modernization, and arms-control policies rooted in and promoting American strength. 

No First Use

One of the most anticipated elements of the Nuclear Posture Review is a possible modification to American nuclear “declaratory policy,” or the conditions under which the United States might employ nuclear weapons in a conflict. Declaratory policy is an important component of the review, since unlike force development or arms control (which take time to bring to fruition), the president could alter declaratory policy at any time. Currently, the United States has a policy of “calculated ambiguity,” in which it threatens to use nuclear weapons in response to “extreme circumstances” including both nuclear and large-scale non-nuclear attacks.

In recent years, the policy of calculated ambiguity has been criticized for being too broad. Then-candidate Biden campaigned on reducing the role of American nuclear weapons by adopting a declaratory policy of “sole use” or “no first use,” in which the United States would promise only to use nuclear weapons in retaliation for an adversary nuclear strike. No first use would narrow the cases in which the United States would use nuclear weapons, foreswearing their employment in response to mass-casualty conventional attacks or chemical and biological weapons. Proponents of no first use argue that the current ambiguous declaratory policy poses escalation risks, since adversaries might become convinced that the United States would attack them in a crisis. A no-first-use pledge would reassure these adversaries and remove provocations that might drive them to violent behavior. Over time, proponents argue, a no-first-use policy would also contribute to greater normative restraint on the use and perhaps even possession of nuclear weapons.

All reasonable people share President Joe Biden’s desire to reduce the importance of nuclear weapons in world affairs, but unfortunately no first use is not the “quick fix” that its proponents claim. Such a policy would not even solve the narrow crisis-stability problem it seeks to address. Adversaries are unlikely to be reassured by a verbal promise to avoid nuclear use, especially one that could be reversed at any time. Nor does it contribute to America’s ability to deter Russian and Chinese aggression, a challenge that is best met with the current policy of calculated ambiguity. Finally, far from advancing the cause of normative restraint, an American no-first-use policy could contribute to nuclear proliferation. Many American partners would see no first use as a reduction in America’s commitment to their security, which might drive them to seek independent nuclear forces.

There are other areas where current nuclear declaratory policy might be improved, especially as it pertains to the relationship of nuclear weapons to emerging capabilities like cyber attacks. But shifting entirely to a no-first-use declaratory policy during the worst security crisis of the post-Cold War era would be a terrible idea, especially for an administration that hopes to rally American partners and create broad coalitions to contain adversaries. Hopefully, the Biden administration has listened to American partners’ concerns and will avoid radically altering declaratory policy.

Missile Modernization

Another critical element of the Nuclear Posture Review will be the Biden administration’s planning guidance for American strategic nuclear forces, especially the mix of delivery systems the United States will invest in over the coming decades. Currently, the United States deploys its strategic nuclear weapons on a “triad” of delivery vehicles: land-based intercontinental ballistic missiles, stealthy submarine-based ballistic missiles, and manned bombers armed with air-launched cruise missiles. After decades of delaying modernization, the American triad is a patchwork of older systems. As a result, the United States plans to replace virtually every missile, submarine, and bomber in its arsenal in the next few decades.

Funding for bombers and submarines enjoys bipartisan support. Modernizing the land-based missile force is more controversial, however, with prominent voices seeking to halt new development. Some opponents of modernizing intercontinental ballistic missiles argue that the missiles are inherently dangerous. American intercontinental ballistic missiles, which are deployed in fixed underground silos, are more vulnerable to an adversary attack when compared to stealthy submarines and mobile bombers. Vulnerable missiles (so the argument goes) could create crisis instability, since an American president might be tempted into launching them precipitously to avoid their being destroyed on the ground. Others oppose modernizing intercontinental ballistic missiles on fiscal grounds. They argue that expensive nuclear modernization will undermine the funding of other security priorities, and that the United States could continue to extend the life of its existing missiles at a much lower cost.

Faced with Putin’s recent nuclear threats, these arguments against intercontinental ballistic missile modernization ring hollow. As with declaratory policy, the United States should recognize that crisis stability depends first and foremost on deterring premeditated and entirely intentional attacks on the United States and its partners. In deterring adversary aggression, the threat of escalation to nuclear war is a feature of the American nuclear arsenal, not a bug. Rendering that threat credible is the best way to prevent opponents from approaching the threshold of conflict in the first place. Intercontinental ballistic missiles contribute to the credibility of American nuclear deterrence. Their responsiveness to command is one of their critical features, since (unlike submarines and bombers) they are ready to execute their mission every hour of every day. Furthermore, the relative vulnerability of any single missile is offset by their wide deployment across the Midwest. Unlike submarines or bombers, large portions of which could be disabled by attacks on a handful of ports and airbases, destroying the intercontinental ballistic missiles force would require adversaries to attack each of 400 silos with multiple weapons, creating an insurmountable “sponge” whose destruction would consume so many munitions as to leave an adversary even more vulnerable to American retaliation.

What’s more, extending the life of existing missiles is neither fiscally realistic nor strategically desirable. Notional plans for life extension can only “save costs” over new missile procurement by cannibalizing existing missiles to support an ever shrinking and less reliable missile force. The argument is not, therefore, really between modernization and life extension, but between modernization and unilateral force reduction. Unilaterally reducing American missile forces at a time when China and Russia are racing to modernize their own forces and threatening their neighbors would weaken deterrence. It would also, ironically, complicate the future arms-control negotiations through which safe reductions in intercontinental ballistic missiles could occur. Such negotiations will be all but impossible if Chinese and Russian leaders can enjoy the benefits of fewer American missiles without making any reductions in their own forces.

Thus far, the Biden administration has signaled support for continued development of next-generation intercontinental ballistic missiles. Hopefully, the new Nuclear Posture Review will confirm this commitment to modernizing American strategic nuclear forces. 

Nonstrategic Nuclear Weapons 

A third important element of the upcoming Nuclear Posture Review will be its approach to nonstrategic nuclear weapons, i.e., those weapons whose ranges are shorter than several thousand miles, and thus fall outside the traditional triad of strategic weapons. Currently, the United States maintains relatively few nonstrategic weapons, especially compared to Russia’s larger arsenal. The 2018 review called for the United States to modestly expand its nonstrategic nuclear forces to deter adversaries from using small nuclear strikes within large conventional conflicts. Since then, the United States has pursued several new capabilities, including a new submarine-launched cruise missile and a low-yield warhead for its submarine-launched ballistic missiles.

Nonstrategic nuclear weapons are one of the most controversial elements of nuclear strategic debates, and the upcoming review could very well trim American nonstrategic nuclear programs. Counterintuitively, nonstrategic weapons attract such controversy because their limited range and yield makes their use that much easier to imagine. The overwhelming threat of strategic nuclear destruction is considered by many to be a reliable deterrent to large-scale nuclear use, but a country armed with a limited nuclear capability might use such a capability on the battlefield, in the hopes that its adversary would back down. Nonstrategic nuclear weapons thus pose a special risk to the norm of nuclear nonuse. Furthermore, by launching a limited nuclear strike, a country might set off a spiral of nuclear attack and counterattack that would result in a much larger and more destructive nuclear war. For these reasons, many experts opposed the 2018 Nuclear Posture Review’s emphasis on expanding American nonstrategic nuclear capabilities.

The real question, though, is how to prevent the use of nuclear weapons at all, not just by the United States. The revisionist political objectives of American adversaries, combined with America’s still-significant conventional combat capabilities, are driving asymmetric responses to traditional American strengths, including the possibility of limited nuclear war. There is no silver bullet to meet this threat, and any solution will require some combination of normative pressure, explicit arms limitation, and broad-spectrum deterrence, including the ability to fight and prevail conventionally against an adversary employing limited nuclear strikes. Yet American leaders must avoid a situation where the destructive power of the strategic nuclear arsenal makes American deterrent threats incredible. Deterring limited nuclear use by adversaries during future crises requires the ability to threaten retaliation against limited nuclear use without employing the larger strategic nuclear force. A small but robust nonstrategic nuclear capability can provide greater credibility to American nuclear threats across the spectrum, making limited nuclear use less likely in the first place.

The right mix of capabilities to deter nonstrategic nuclear attack is a tricky subject, but it undoubtedly includes a modernized and diverse nonstrategic nuclear component. Submarine-based nonstrategic weapons could contribute to that deterrent mission in the same way that they do the strategic one: by creating redundancies in striking capability that make it harder for an adversary to avoid nuclear retaliation. Other types of weapons might feasibly achieve the same objective. If it decides against submarine-based nonstrategic nuclear weapons, the Biden administration should outline its own plan to diversify American capabilities. The new Nuclear Posture Review provides an opportunity to build on the 2018 review’s work in addressing this threat, rather than closing the door on this important discussion. 

Arms Control 

A final point to watch in the upcoming Nuclear Posture Review is its roadmap for future nuclear-arms-control negotiations to limit the Russian and Chinese arsenals. In a world of rising international tensions, next steps on arms control remain frustratingly elusive. Russia’s cheating on legacy arms-control agreements had already put the regime under tremendous strain. Now, the Biden administration’s budding “Strategic Stability Dialogue” is unlikely to survive Russia’s invasion of Ukraine. China, in turn, has not shown any serious interest in arms control, pursuing rapid nuclear expansion instead. As a result, there is a very strong chance that when the New Strategic Arms Reduction Treaty (New START) expires in 2026, the nuclear arsenals of the great powers will be totally unconstrained for the first time since 1972.

The breakdown of U.S.-Russian arms control is a significant loss for both countries. To date, the United States has struggled to produce an actionable plan for restoring arms control dialogue with China and Russia. Some experts now favor downplaying formal agreements in favor of looser policies aimed at reinforcing normative restraints on nuclear weapons, in the hopes of preserving at least portions of the previous arms control regime.

The United States should bolster normative restraints on the use of nuclear weapons, but norms alone will not move adversaries like China and Russia to curtail their nuclear ambitions. In the long run, a “dual track” strategy represents the best way to create conditions under which rigorous, formal, and verifiable arms limitation could reemerge.  This was the approach that the United States and its partners practiced during the Cold War, most famously in the leadup to the 1987 Intermediate-Range Nuclear Forces Treaty. Under the dual-track approach, the United States and its partners committed to deploying robust nuclear forces for self-defense and deterrence, while simultaneously negotiating nuclear-arms limitation with the Soviet Union. A dual-track approach leverages the paradoxical yet strong synergies between building arms and negotiating their limitation, in which the construction of new weapons incentivizes adversary participation in negotiation, and the conclusion of favorable agreements improves the balance of forces.

Success in arms limitation requires strong leadership, effective negotiation, fortuitous political circumstances, significant time, and a fair amount of luck. The dual-track approach is no panacea, but it does provide the basic structure under which rigorous, formal, and verifiable arms limitation could reemerge over the longer term, in ways that purely normative constraints cannot. The Nuclear Posture Review would do well to embrace it as the most promising way forward. 

Conclusion

Putin’s unprovoked attack on Ukraine and his outrageous nuclear threats have done the United States a great favor. Putin has thrown into sharp relief the tremendous threat to international security in the early 21^st century posed by the aggressive and volent designs of authoritarian regimes. International security will depend first and foremost on deterring these hostile actors in partnership with our allies. Policies aimed at improving crisis stability that weaken deterrence will therefore be self-defeating, achieving neither stability nor security. Since our adversaries are determined to leverage their nuclear arsenals in the pursuit of their goals, any program to deter and contain them will require a recommitment to a strong American nuclear deterrent.

The Nuclear Posture Review should reflect this reality: This means taking unapologetic steps to bolster deterrence through robust nuclear modernization, reassuring partners by demonstrating Washington’s commitment to their defense, and setting out an ambitious plan to build future arms control by negotiating from strength.

John D. Maurer is a professor of strategy and security studies at the School of Advanced Air and Space Studies (SAASS), Air University, and a non-resident fellow at the American Enterprise Institute (AEI). His book on the history of American nuclear strategy and arms-control policy, Competitive Arms Control, is forthcoming with Yale University Press. The views expressed are his and do not reflect the official policy or position of the Air Force, Department of Defense, or the U.S. government.

Image: U.S. Air Force (Photo by Tech. Sgt. Corban Lundborg)

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