Science, Technology, and Public Policy

The nuclear weapons taboo is considered one of the strongest norms in international politics. A prohibition against using nuclear weapons has seemingly shaped state behavior for nearly seven decades and, according to some observers, made nuclear use ‘unthinkable’ today or in the future. Although scholars have shown that nuclear aversion has affected decision-making behavior, important questions about the nuclear taboo remain unanswered. This article seeks to answer a basic question: How durable is the taboo? We develop different predictions about norm durability depending on whether the taboo is based primarily on moral logic or strategic logic. We use the comparable case of the norm against strategic bombing in the 20th century to evaluate these hypotheses. The logic and evidence presented in this paper suggest that the norm of nuclear non-use is much more fragile than most analysts understand.

Some experts are increasingly concerned that China’s modernization will lead to a Chinese nuclear “breakout”—a pursuit of a nuclear-warfighting capability or a “sprint to parity” with the United States. David Logan (“Hard Constraints on a Chinese Nuclear Breakout,” Vol. 24, Nos. 1–2, 2017, pp. 13–30) rightly suggests that such a nuclear breakout would be constrained not only by China’s “soft” nuclear policy but also by “hard” technical constraints. I would emphasize that it is the former that has been the first principle guiding China’s nuclear-force development. That some of the “hard” technical constrains have resulted from this “soft” guidance demonstrates China’s commitment to a small deterrent force. It is difficult to imagine that the future development of China’s nuclear force would eventually overthrow these first principles. In fact, there is no evidence that China will change its long-standing nuclear policy.

If we had the technology to detect nuclear materials remotely it could help deter smuggling and make it easier to monitor international nuclear agreements. Several recent breakthroughs, if followed up with continued research and funding, could deliver on this promise. They include technological advances in x-ray and neutron radiography; a method that measures how plasma breaks down when exposed to a radioactive source; and developments in antineutrino detection. While all require more development and testing, they are important steps as the global need for ways to detect nuclear materials grows.