Much of what we think we know about the politics of nuclear weapons is derived from the bipolar Cold War nuclear rivalry between the United States and the Soviet Union. That’s not going to help us in Asia.
Perhaps the world’s most important center of geopolitical competition, the Asia-Pacific region is certainly its most complex nuclear security environment. It is home to established nuclear powers, such as Russia, China, India, and Pakistan; states that have significant “latent” nuclear capabilities, including Iran, North Korea, Japan, and South Korea; and a handful more that may yet seek to join the nuclear club. We need a better grasp of this changed Asian deterrence landscape and how it will affect U.S. national security interests, for simply applying bipolar models from the past is inadequate and potentially disastrous.
The most important and fundamental differences with the Cold War are that, at present, the major nuclear-armed states each have multiple nuclear-armed adversaries, and these competitor states are not aligned with one another.
This has a number of important implications for U.S. nuclear policy. First, U.S. officials need to move away from thinking about U.S.“nuclear strategy” in the singular and toward a new model of separate strategies, postures, and capabilities for each potential adversary. The old approach made sense during the Cold War when, for all intents and purposes, Washington faced a single nuclear-armed rival. But a single nuclear strategy does not work for a world with multiple nuclear adversaries. For example, a traditional assured retaliation strategy may be sufficient to deter China, with its relaxed nuclear posture. But to counter Russia’s nuclear “escalate-to-de-escalate” strategy, Washington must cultivate the ability to deter limited nuclear war. And for plausible North Korea nuclear attack scenarios, it must also be prepared for nuclear preemption.
Second, extended deterrence and assurance are also challenged by Asian nuclear multipolarity. Asian allies must question whether the U.S. nuclear umbrella, which was originally extended to protect the U.S. and allies from a specific nuclear threat, applies equally to each and every new nuclear danger that arises. As growing Chinese and North Korean nuclear capabilities place the U.S. homeland in ever greater danger, for example, East Asian allies wonder whether Washington remains willing and able to provide for their security. For decades, stability in East Asia has been undergirded by overwhelming U.S. power and to preserve this equilibrium, Washington must strive to maintain a clear advantage in strategic capabilities over potential Asian adversaries.
Third, turning to arms races and arms control, the United States cannot only worry about traditional action-reaction arms race dynamics, but it must also be attuned to the possibility of action-reaction-reaction-reaction arms races as enhancements to U.S. capabilities, in the form of missile defenses, hypersonic glide vehicles, or other new technologies, ripple through a string of nuclear powers from China to India to Pakistan, and perhaps others. This chain also creates opportunities, however, for new and more creative arms control arrangements between states in different positions that lock in asymmetric limits or that link unlike capabilities. For example, there may be room for negotiated constraints that allow Washington to assure Beijing that it does not seek to undermine China’s nuclear retaliatory capability in exchange for China agreeing to grant a quantitative nuclear superiority to the United States.
Fourth, Asia’s multipolar nuclear environment increases the risks of nuclear instability that result from overlapping redlines and strategic dynamics. Layered against simmering tensions in the South China Sea, the Korean Peninsula, the Senkaku/Diaoyu Islands and elsewhere, there is a low but non-zero probability that the nuclear taboo could be broken in Asia. These and other threats to nuclear stability should be addressed in official diplomacy, tabletop exercises, and Track II dialogues with both Washington’s friends and enemies because the time to avoid nuclear escalation is now, not in the heat of a crisis.
Fifth, and finally, the number of nuclear powers in the region is not magically capped. Washington must hold the line on future nuclear proliferation in the region and, where possible, take proactive steps to roll back existing nuclear capabilities. Past predictions of widespread proliferation in Asia have been exaggerated, but with each new nuclear power, the demand and supply-side drivers of nuclear pursuit increase, making future proliferation “cascades” more likely. Fortunately, there is also an element of good news as Washington and Beijing both have strong incentives to limit additional entries into Asia’s nuclear club. Dealing with North Korea will be difficult, but dissuading and halting nuclear programs in new proliferant states could become an important pillar of bilateral cooperation between Washington and Beijing for decades to come.
The challenges posed by a multipolar nuclear Asia are severe, but not insurmountable. In the past, the United States has managed to understand, adapt to, and thrive in equally challenging security environments. By following the above steps, there is reason to believe that addressing the challenges of a multipolar nuclear Asia will be no different.