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Introduction: Dangerous Dynamism in Asia’s Nuclear Future

One of the defining elements of the post-Cold War era has been the diffusion of power away from the two superpowers. This has occurred across a wide variety of measures, including nuclear weaponry. In particular, since the end of the Cold War, proliferation across states and increasing arsenal capabilities within some of them have characterized Asia's international security affairs. Given the importance of nuclear weapons to the development and conduct of the Cold War, we should expect these changes in the post-Cold War era to be similarly important.These changes have been the subject of significant scholarly analysis already. Dubbed the "second nuclear age" by eminent strategists Colin Grey and Paul Bracken, this epoch seems to pose new dangers and challenges.1 Important debates have developed about the degree to which the most engaged dyad-India and Pakistan-is more dangerous than the dyads in the Cold War, to which nuclear weapons provided apparent stability.2 Other studies have examined a broader range of countries facing this new environment.3 A burgeoning quantitative literature surveys both Cold War and post-Cold War crises and dyads to evaluate a wide range of hypotheses about stability and coercive leverage.4To further these discussions, the National Bureau of Asian Research (NBR) has initiated a broad-based research program entitled "Approaching Critical Mass: Asia's the Multipolar Nuclear Future." With funding from the Carnegie Corporation of New York and John D. and Catherine T. MacArthur Foundation, the project began with the publication of Strategic Asia 2013-14: Asia in the Second Nuclear Age in 2013.5 Building on this and other work, NBR in January 2014 convened a conference jointly with the S. Rajaratnam School of International Studies in Singapore to further explore several important themes.Several key themes emerge from the essays in this roundtable. First and foremost, it is important to find the right geometric analogy to describe contemporary nuclear dynamics in Asia. Two promising candidates are nuclear triangles and nuclear hierarchies. While, as the essay by Rajesh Basrur reminds us, it is true that bipolar dynamics were not the only form of interaction during the Cold War, competition with the Soviet Union was the dominant driver for the United States for nearly the entire period. Today, for several countries, at least two other nuclear states play an important constitutive role in shaping nuclear policy. Thus, in Asia the United States worries about both Chinese and North Korean nuclear developments. The nature of the nuclear capabilities of those two states is dramatically different, and so is the nature of the strategic competition between the United States and each of them. This at least raises the possibility that steps taken to address one potential competitor are suboptimal with regard to the other. Similarly, P.K. Singh's essay cogently makes the point that Indian strategic dynamics must be situated in a broader regional context that includes both Pakistan and China. Other interactive triangles may include the United States, China, and India or the United States, Russia, and China. Triangles might vary in terms of the degree to which they are tightly coupled (or not), in the symmetry across the different legs of the triangle, and likely in other dimensions. Further development of this concept is likely to be useful.Additionally, the essays raise the issue of nuclear hierarchies. While different arsenal sizes existed among different actors during the Cold War, today there is a greater degree of interaction among states with such different sized nuclear forces. Arsenals run from barely existent (North Korea) to midsized (China, India, and Pakistan) to large (United States). Although analogues to each existed in the Cold War (South Africa, France, and the Soviet Union, respectively), there was limited strategic interaction across those categories. Today, there is much more. …