Asia's Multipolar Nuclear Future

NBR spoke with Matthew Kroenig (Georgetown University) about his forthcoming NBR Special Report, “Approaching Critical Mass: Asia’s Multipolar Nuclear Future,” which will be available on June 22. The report explores the dynamics of nuclear multipolarity in Asia while elaborating on the unique challenges and risks for both Asian states and U.S. foreign and defense policy. In this Q&A, Dr. Kroenig comments on the key issues examined in the report and explains the practical implications of a multipolar nuclear order.

Your upcoming NBR Special Report “Approaching Critical Mass: Asia’s Multipolar Nuclear Future” defines a multipolar nuclear order as an “international system in which multiple nuclear powers regularly interact.” How is this order conceptually different from the bipolar nuclear order?

Most of our understanding of nuclear strategy—nuclear postures, arms races, arms control, escalation, assurances, proliferation—derives from the Cold War bipolar order. Asia today, however, is a region with a multipolar nuclear order, including both established and latent nuclear states. By “multipolar,” I mean multiple powers, regardless of whether they are great powers or poles in the broader international system as defined by international relations theorists. There are seven states in the Asia-Pacific that are known or believed to possess nuclear weapons: the United States, China, Russia, India, Pakistan, Israel, and North Korea. Latent nuclear states include Japan, South Korea, and Iran; these countries all have the capability to build nuclear weapons in short order should they decide to do so. Additionally, Vietnam, Malaysia, Australia, and other regional actors could explore nuclear weapons development in the future.

The United States has historically been concerned foremost with the nuclear forces of the Soviet Union—and later, Russia—and designed strategies to confront and address the nuclear capabilities of a single actor. Today, however, nuclear nations must develop strategies with multiple potential nuclear adversaries in mind. This situation requires new thinking on the critical components of nuclear dynamics that influence policymaking, including nuclear arms races, arms control, proliferation, extended deterrence, assurance, and nuclear escalation. Simply applying the bipolar model to an increasingly multipolar and complex nuclear order will prove misleading and could point us toward incorrect and potentially disastrous policy choices.

What are some examples in nuclear policy that demonstrate the qualitative difference of operating in a multipolar nuclear world?

The clearest examples are in nuclear strategy and posture. No major nuclear power enjoys the luxury of worrying about only one nuclear adversary, so nuclear states must have a strategy and posture that take multiple actors into consideration. For example, at present the United States must manage threats posed by nuclear peer Russia while taking into consideration the strategic forces of both China and North Korea. The same is true for other nuclear-armed powers: China must take into account Russia, India, and the United States, while India must consider both Chinese and Pakistani capabilities. These situations raise the question of how and to what extent a state’s nuclear strategy and posture should be adjusted in response to multiple nuclear actors. Some countries might choose to devise a single, overarching nuclear strategy that deals with all potential adversaries. Others might tailor strategies and policies to address the threat posed by each potential adversary. The second option is more appropriate for the United States because the challenges posed by Russia, China, and North Korea involve different balances of forces and interests and therefore require different approaches.

Another significant problem is that the multipolar nuclear order may produce distinct arms race dynamics and challenges for arms control. During the Cold War, the United States was concerned with the prospect of an arms race with only the Soviet Union when it developed or deployed novel military nuclear capabilities. In a multipolar nuclear order, when a country changes its nuclear capabilities or posture, there is a substantial risk that multiple countries will respond to the initial change. For example, if the United States makes advances in its ballistic missile defense systems or conventional prompt global strike capabilities, these developments could induce China to increase the size of its arsenal, improve penetration aids on warheads, or even abandon its “no first use” doctrine. In turn, Beijing’s moves could trigger fear in New Delhi that India’s strategic forces will soon be inadequate to deter China, prompting further enhancements of India’s nuclear weapons program. States are more likely to fall into such a cycle in a multipolar nuclear order than in a bipolar one.

Therefore, when countries contemplate changes to their posture and force structure, they must anticipate the full range of possible reactions throughout the multipolar order. This does not necessarily mean that countries should not make appropriate changes, but rather that they should scan a wider horizon in considering the potential consequences of their actions. The list of emerging strategic capabilities this applies to is vast: from tactical nuclear weapons in South Asia, anti-satellite missiles in East Asia, and even the maturation of Chinese and Indian ballistic missile submarine forces.

In a multipolar nuclear era, one nation, such as North Korea, could trigger a chain reaction or nuclear cascade in the broader region. What are the implications of this dynamic for U.S. nuclear strategy, particularly in terms of the credibility of U.S. assurances to its regional allies?

In a multipolar nuclear order, providing extended deterrence becomes a more difficult task than it already is. The credibility of extended deterrence hinges on a U.S. commitment to defend an ally, potentially with nuclear weapons if the situation escalates. As an adversary’s nuclear capacity grows—and particularly as a state gains the ability to strike the U.S. homeland—the risk that the United States runs by committing itself to providing extended nuclear deterrence also increases. Eventually, there is the danger that the commitment is called into question. During the Cold War, for example, French president Charles de Gaulle famously asked, “Would the United States really trade New York for Paris?” Doubts about Washington’s willingness to make that trade influenced the French decision to pursue an independent nuclear force.

As China’s capability to strike the U.S. homeland improves with the fielding of newer, road-mobile intercontinental ballistic missiles and as North Korea gains the ability to place a nuclear warhead on a missile for the first time, it would not be surprising if some Asian allies begin to feel insecure about the credibility of extended deterrence and question the willingness of the United States to fulfill its commitments to protecting their country with nuclear weapons. As the number of nuclear threats increases, extended deterrence will be further stretched as local security clients realize that the United States, as a nuclear patron, may have multiple extended deterrence requirements that draw on the same military resources. In addition, Washington has often extended the nuclear umbrella to address a specific nuclear threat, but allies may not be convinced that the umbrella will also apply to every new, emerging nuclear challenge. For example, U.S. nuclear guarantees may have successfully assured Japan about threats from Russia and China, but do they apply equally well to North Korea? What about future proliferants in Asia? The answer is not clear.

Given the growing nuclear threats in Asia, including North Korea’s advancing program, how can the United States dissuade its allies from pursuing nuclear weapons programs?

U.S. allies in Asia, such as Japan and South Korea, could decide to develop nuclear weapons in the future. These countries already have the industrial capability to go nuclear in a short period of time. The only thing that is preventing them from pursuing such a path is their political choice not to do so. The U.S. security guarantee is almost certainly one of the most critical factors contributing to that choice. The Asian security architecture post-1945 was built on overwhelming U.S. military power. That power deterred, first, Soviet expansion and, later, aggression by China and North Korea and has reassured U.S. allies such as Japan and South Korea. The foundations of this architecture are starting to shift with China’s buildup of its conventional forces and modernization and expansion of its nuclear arsenal, in addition to North Korea’s continuous development of missiles and nuclear weapons.

To reassure U.S. allies, therefore, it is of paramount importance that the United States maintain military superiority in the region. As long as the U.S. security guarantee remains strong and credible, we will be able to dissuade our Asian allies from going down the nuclear path. To attain this goal, the United States must further increase defense spending to ensure that it has the capabilities to deal with any possible scenario in Asia. Furthermore, the United States and its allies should explore expanding and increasing deterrence mechanisms such as forward deployments, exercises in the region, and trilateral discussions—including tabletop exercises that involve nuclear-use scenarios. Reinforcing extended deterrence will not be an easy process, as it will require constant effort from Washington to make sure that its alliance partners feel reassured in the face of growing nuclear threats.

In your forthcoming NBR Special Report, you call the Asia-Pacific “the world’s most complex nuclear environment in the 21st century.” Beyond maintaining superiority, what other steps can the United States take to prevent nuclear proliferation in Asia?

The United States needs to work harder to prevent the proliferation of nuclear weapons to additional countries in Asia. This entails reassuring our allies, continuing to restrict the spread of sensitive nuclear materials, and working to ameliorate the security conditions that feed countries’ desires for nuclear weapons in the first place.

Furthermore, the United States could cooperate with other major powers in Asia, especially China, in preventing the further spread of nuclear weapons in the region. One of the most important brakes on future proliferation is that the two largest powers in the region both have a strong incentive to restrict entry into the nuclear club. Dealing with North Korea will be more difficult for a variety of reasons, but dissuading and halting nuclear programs in new proliferant states could be an important pillar of future bilateral cooperation between Washington and Beijing in the decades to come.

Matthew Kroenig is an Associate Professor in the Department of Government and School of Foreign Service at Georgetown University and a Senior Fellow in the Brent Scowcroft Center on International Security at the Atlantic Council.

This interview was conducted by Claire Chaeryung Lee, and Intern at NBR.