Modernizing nuclear arsenals: Whether and how

In nuclear arms control and disarmament, one sees two competing trends at play: an aspiration in many quarters to eliminate nuclear weapons and a practical desire among nuclear weapon states to modernize their arsenals. What sort of balance between these forces can be achieved?

Nuclear powers feel the need to modernize their arsenals for three main reasons. First, in today's international security environment, they still see nuclear weapons as necessary, mainly for deterrence purposes. Second, nuclear weapons continue to play a very important role in maintaining global strategic stability. Third, as long as nuclear arsenals exist, modernization is necessary in order to keep weapons safe and reliable.

Advocates for disarmament, meanwhile, argue that nuclear weapons must be prohibited and arsenals destroyed because of the disastrous consequences that would befall the human race if these weapons were ever used. Nuclear weapon states themselves, even as they emphasize the necessity of modernizing their arsenals, acknowledge that nuclear weapons ought to be eliminated eventually. For example, the Obama administration in 2009 launched a vigorous initiative toward achieving a world free of nuclear weapons.

But today's heavy US investment in nuclear modernization seems at odds with the objective of nuclear disarmament. Between 2014 and 2023, the United States is expected to spend $355 billion on modernization. Reductions in US warheads envisioned under the New Strategic Arms Reduction Treaty (New Start) will be offset by upgrades in the quality of the US arsenal. Meanwhile, Washington's Prompt Global Strike and ballistic missile defense programs have posed new challenges to strategic stability.

China also feels the need to modernize its nuclear forces—in order to enhance survivability and maintain a credible minimum nuclear deterrent. But these are China's only objectives for its nuclear weapons. Among the five recognized nuclear weapon states, China is the only nation that has committed to an unconditional no-first-use policy. This policy has consistently placed restraints on China's nuclear force development (which, in any case, has never been a top priority in Beijing's military modernization drive). China consistently advocates for a world free of nuclear weapons. It has never participated in a nuclear arms race. It has never deployed nuclear weapons in any other country's territory.

Unfortunately, most nuclear-armed states—including the United States—still assign nuclear weapons a very important role in their strategies for safeguarding security. Washington, in its most recent Nuclear Posture Review, decided to no longer assign certain marginal or unrealistic tasks to nuclear weapons, but made no fundamental changes to the role of US nuclear weapons or to nuclear war-fighting strategy. As long as nuclear weapons play such a crucial role in US strategy, and as long as the United States maintains its desire for absolute security, Washington will not reduce its nuclear arsenal to relatively low levels or make dramatic changes to its current modernization program. Much the same holds true for Russia.

So, nuclear-armed nations see modernization as indispensable, but further disarmament progress seems impossible as long as modernization programs continue apace. What's the way out of this bind? The key—because national nuclear strategies determine the direction of nuclear programs—is to adjust national strategies so that less emphasis is given to the role of nuclear weapons.

If the United States and Russia significantly alter their nuclear strategies, further substantial reductions in arsenals are possible. If the two nations' arsenals are reduced, other states will be encouraged to consider how and when they might participate in multilateral disarmament processes. Multilateral disarmament will be no easy task—as shown by the history of US-Russia disarmament negotiations, even bilateral processes are very difficult. Still, further progress by the United States and Russia could serve as an inspiration to other nuclear-armed nations.

But there's a further complication—missile defense systems and Prompt Global Strike capacities pose a serious threat to strategic stability and to disarmament. New Start imposed no restrictions on the development of ballistic missile defense or advanced conventional weapons, and developments in either technology could trigger a renewed nuclear arms race. Consequently, great discretion is required regarding the development and deployment of such systems. (New Start, incidentally, also leaves the United States with a strong nuclear "upload" capability. That is, the United States retains ample space on deployed missiles to redeploy warheads that have been taken out of service. Russia, in contrast, has little upload capacity.)

Eliminating nuclear weapons does not appear feasible at this stage. Modernizations of nuclear arsenals are certain to go forward. But it's possible—and very important—to achieve a balance between modernization and disarmament. Under such an approach, nuclear strategy would be adjusted so that nuclear weapons assumed less importance in national security. The practical reasons for possessing nuclear weapons would gradually disappear. All nuclear-armed countries would be encouraged to reduce their arsenals. But it's the United States and Russia, the two nuclear superpowers, that must take the lead, establish trust, and set a good example for other nations.

My childhood dream was to star in the National Basketball Association. But I stand only six feet one inch tall, I'm entering my late 30s, and I haven't played competitive basketball in over 15 years. My chances of playing at the professional level are essentially zero. Some might argue that, if I am to have any hope of realizing my boyhood wish, I should spend my days running wind sprints and practicing free throws. But that path would improve my chances from none to extremely slim, and would certainly take away from my duties as a professor, researcher, and analyst. In the end, it simply isn't worth ruining the life I have in order to chase a fantasy.

The same can be said of the United States' choices regarding its nuclear posture. Over the next decade and beyond, the United States will go through a much-needed modernization of its aging nuclear capabilities, and these plans enjoy strong bipartisan support. But some critics argue that the modernization project conflicts with stated disarmament goals, including President Obama's vision of bringing about "a world without nuclear weapons."

The fact, however, is that the world is characterized by intense security competition and sometimes outright conflict. Though some observers hoped that the end of the Cold War would bring the end of history, political discord among great powers has returned in recent years. Russia is using force to redraw the map of Europe. China is asserting revisionist territorial claims in East Asia. Over the past two decades, conventional military dominance has allowed the United States to de-emphasize its nuclear weapons, but the US conventional advantage is eroding as Russia and especially China build up their non-nuclear military capabilities. Moreover, nuclear weapons remain the ultimate instrument of military power—and Washington's potential adversaries, including Russia, China, and North Korea, are modernizing their nuclear arsenals with an eye toward using those weapons in the event of conflict with the United States.

This is reality.

Nonetheless, some argue that achieving the fond hope of complete nuclear disarmament requires the United States to cut its arsenal and refuse to modernize its forces. But other countries will not blindly follow Washington's lead. In recent years, as the United States has slashed the size of its arsenal, other countries have moved in the opposite direction, building up their nuclear forces. Complete nuclear disarmament may be desirable, but achieving it will require nothing less than a major transformation of the international political system. Simply allowing the US arsenal to rust away, therefore, will not meaningfully affect chances for eliminating nuclear weapons worldwide.

Failure to modernize would not contribute to disarmament—but more than that, it would be irresponsible. A crippled US nuclear force would embolden enemies, frighten allies, generate international instability, and undermine US national security. In other words, it would risk ruining the world that currently exists.

Rather than preparing for an alternate reality, therefore, Washington needs to build the nuclear forces that it needs in this reality. The United States must maintain a robust nuclear posture and fully modernize its nuclear forces, as planned. This means upgrading all three legs of the nuclear triad, refurbishing nuclear warheads, modernizing the production complex, and, if necessary, summoning the political will to build new capabilities to meet new demands. As Defense Secretary Chuck Hagel put it in November, "Our nuclear deterrent plays a critical role in assuring US national security, and it is [the Defense Department's] highest priority mission. No other capability we have is more important."

Some might argue that modernization in the United States will spur reactions in other states, contributing to a new arms race—but, as pointed out above, modernization plans are proceeding apace in the rest of the world quite apart from any decisions being made in Washington. Critics also cite cost as an obstacle, but, at its peak, the nuclear upgrades will only account for around 5 percent of the defense budget. Thus, nuclear weapons provide a strategic deterrent at a reasonable price. Or, as incoming Defense Secretary Ashton Carter said in 2013, "nuclear weapons don't actually cost that much."

In sum, there is no good reason for the United States not to follow through on its planned modernization of nuclear forces. Perhaps one day we will be pleasantly surprised by an opportunity to live out our fantasies. But until then, we must live up to our responsibilities.

Most nuclear weapon states, including the United States and Russia, have often declared their commitment to getting rid of nuclear weapons. But no nuclear weapon state will feel ready to abandon its nuclear capabilities unless all other nations do likewise. Nuclear arms are therefore likely to remain in military arsenals for a long time and nuclear weapons will continue to be refurbished. But even if one accepts as inevitable the modernizations of nuclear arsenals, can they be managed in such a way that they don't create obstacles to nuclear arms reductions and to complete disarmament in the long run?

The history of Russia-US arms control negotiations provides many examples of nuclear modernizations that created no obstacles to reductions—and that in fact were conditions for cuts. In particular, the US Senate's approval of New START in 2010 was conditioned on accelerated funding for modernizing the US nuclear weapons complex and ensuring the modernization of delivery systems. The logic in such a calculation is quite clear: Arsenal reductions must not create an appearance of weakened security. If nuclear forces are reduced in numerical terms, the need emerges to enhance the efficiency and survivability of remaining forces. 

In any event, history shows that nuclear-armed states continually modernize their nuclear weapons. But the factors motivating modernization, and the relative importance of those factors, have varied. In the Russia-US relationship, modernization has been driven by four factors: first, the emergence of new technologies making nuclear arms more efficient and allowing them to be maintained in safer, more secure ways; second, the development by an adversary of disruptive technologies such as air and missile defenses, antisubmarine warfare, and offensive long-range high-precision arms; third, a desire to broaden the functional capabilities of delivery systems originally designed for nuclear missions exclusively; and fourth, the limited service life of existing systems.

Conditions for the Cold War arms race were created by the first two factors—the emergence of new technologies that made nuclear arms more efficient and, especially, the development of disruptive technologies. Ballistic and cruise missiles as well as supersonic heavy bombers were a response to the development of air defenses, while nuclear-powered submarines and submarine-launched missiles with intercontinental range were a response to the evolution of antisubmarine warfare. The impact of ballistic missile defense during the Cold War is somewhat questionable—the effectiveness of ballistic missile defense technologies was quite limited in those days. Still, one cannot exclude the possibility that the Anti-Ballistic Missile Treaty performed an important function by limiting these technologies. And who knows how different the evolution of strategic arms might have been if the parties had agreed to limit disruptive technologies such as air defenses and antisubmarine warfare? What's certain is that, during the Cold War, the qualitative modernization of nuclear arms proceeded so fast that new systems emerged long before the service lives of older systems were exhausted.

The end of the Cold War brought changes in the balance of factors affecting modernization decisions. Though certain US strategic programs continued in the early 1990s due to inertia (a build-up, for example, in new nuclear-powered ballistic missile submarines), a general understanding was reached in the United States that the nation's nuclear arsenal was too large and had lost much of its value in the new geopolitical environment. The primary motivating factor for US modernization thus became a desire to make strategic delivery systems more "usable." The effort began by equipping heavy bombers with high-precision conventional weapons and converting them for non-nuclear roles. Air- and sea-launched long-range cruise missiles were also equipped with conventional warheads. Another development in this vein was the advent of the Prompt Global Strike program, which began as a plan to replace nuclear warheads on ballistic missiles with conventional warheads.

The United States has been modernizing its delivery systems continuously for two decades. But these delivery systems are approaching the end of their originally planned service lives, and their potential for further modernization is limited. On the other hand, accumulated technology advancements are now spurring the United States to build a new generation of delivery systems.

In Russia, for almost two decades, modernization programs suffered from persistent underfunding. The service lives of missiles inherited from the Soviet Union have been extended by factors of two to three. Indeed, Russia's ambitious programs to deploy new delivery systems—which will absorb the lion's share of a broader rearmament plan that, through 2020, will cost 20 trillion rubles—can be explained first of all by the impossibility of extending indefinitely the service lives of existing weapons. But a second factor has played a role in Russia's decision to develop new delivery systems. Specifically, the threat of US ballistic missile defense deployments in Europe, along with the development of US strategic conventional weapons, have been strong arguments in favor of developing new heavy missile and mobile railway systems. (However, it's unclear how these programs will evolve as Russia's economic situation deteriorates.)

Diverging perceptions. In both the United States and the Soviet Union (and later Russia), nuclear reductions were possible in the late 1980s and early 1990s because both sides realized that their accumulated arsenals were excessively large and the arms race was senseless. Since then, arsenals on both sides have diminished progressively. Modernization programs are unlikely to reverse this trend, despite deterioration in US-Russia relations over the last few years. But the two nations no longer perceive similar incentives where making further cuts is concerned.

In the United States, many people still recognize that the US arsenal is too large. President Obama, for example, announced in a 2013 Berlin speech that he would "seek further negotiated cuts with Russia to move beyond Cold War nuclear postures." This proposal seems to have a strong pragmatic goal—to reduce the costs of future modernizations by cutting excess forces. In Russia, however, a number of current trends don't encourage similar viewpoints. In particular, many Russians perceive the unconstrained development of US ballistic missile defense and precision guided munitions as new threats that require a response. Often, these perceptions are influenced too much by emotion. Nonetheless, Russia's industrial and financial resources are limited. Moscow has no ability to influence the qualitative development of US arms. In such a situation, further US development of missile defense and precision guided munitions makes Russia less interested in pursuing the bilateral negotiation process and more inclined to reduce the transparency of its nuclear arsenal.  

In the best-case scenario going forward, US modernization programs will have a minor negative impact on bilateral relations. In the worst case, they will become an additional irritant in an already complex relationship. But it is unlikely that bilateral negotiations toward further cuts can begin unless US-Russia relations improve radically.

Even when prerequisites are met for further dialogue on nuclear arms reductions, ballistic missile defense and conventional strategic arms will remain crucial obstacles. Therefore it's important that the United States limit development of such weapons—or direct their development in such a way that other states won't have cause to worry about the survivability of the smaller nuclear arsenals that would result from agreed arms reductions.