International Relations

Calder Walton writes that Soviet espionage inside the Manhattan Project would change history. By the end of World War II, Stalin's spies had delivered the secrets of the atomic bomb to the Kremlin. This accelerated Moscow's bomb project. When the Soviets detonated their first atomic weapon in August 1949, it was a replica of the weapon built at Los Alamos and dropped by the Americans on Nagasaki.

This year's G7 summit in Hiroshima sees nuclear disarmament and non-proliferation sitting high on the agenda, amid rising tensions between the nuclear states and an increasingly divided international order.  Six contributors offer their analyses, including the Belfer Center's Mayumi Fukushima.

Scott Sagan asked Joseph S. Nye to revisit Nuclear Ethics, a book he published in 1986, in light of current developments in world affairs. In doing so, he found that much had changed but the basic usability paradox of nuclear deterrence remains the same. 

Joseph Nye considers U.S. options for risk reductions as nuclear threats escalate and China-Taiwan tensions rise.

Mariana Budjeryn's Inheriting the Bomb tells the story of how Ukraine came into possession of the world's third-largest nuclear arsenal—larger than the combined stockpiles of China, France, and the United Kingdom at the time—and decided to disarm peacefully a few years later. Ukraine's denuclearization was far from a straightforward process. After initially renouncing nuclear weapons, Ukrainian officials sought recognition that their newly independent country was a rightful heir to part of the Soviet cache, deserving of equal treatment, financial compensation, and pledges that disarmament would not endanger Ukraine's security. 

There seems to exist a general consensus on how to conceptualize cooperation in the field of international relations (IR). The authors argue that this impression is deceptive. In practice, scholars working on the causes of international cooperation have come to implicitly employ various understandings of what cooperation is. Yet, an explicit debate about the discipline's conceptual foundations never materialized, and whatever discussion occurred did so only latently and without much dialog across theoretical traditions. In this article, the authors develop an updated conceptual framework by exploring the nature of these differing understandings and situating them within broader theoretical conversations about the role of cooperation in IR.

Stephen Walt explains why Putin understood that Ukraine's fate was more important to Russia than it was to the West.

With rational decision-making, the likelihood of strategic nuclear exchange should be zero. But emotions can create uncertainty, contradicting the expectations of the rational cost-benefit assumptions undergirding deterrence theory.

Abolghasem Bayyenat argues that without the JCPOA restrictions in place, Iran's nuclear program will expand and continue to acquire irreversible technical knowledge and competencies.

Joseph Nye writes that Russian aggression and nuclear saber rattling have reminded us that the likelihood of nuclear war is a matter of both independent and interdependent probabilities. Paradoxically, reducing the probability of an all-out catastrophe requires that we learn to accept a certain degree of risk and uncertainty.