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The Once and Future Threat of Nuclear Weapon Testing

The Nuclear Non-Proliferation Treaty (NPT) is the central security instrument of the United States and the world community. It is based on a strategic bargain between the five nuclear weapon states in the NPT (the United States, the United Kingdom, France, Russia, and China) and the 185 non-nuclear-weapon parties to the treaty. The current worldwide moratorium on nuclear weapon testing and the intended ultimate conversion of that ban to legally binding treaty status by bringing the Comprehensive Test Ban Treaty (CTBT) into force are essential to the long-term viability of this strategic bargain. But some Trump administration officials have signaled hostility to the CTBT and an interest in the United States resuming nuclear weapon testing, which could cause a catastrophic unraveling of that bargain.

Soon after 1945 and the end of the Second World War, as a symptom of the Cold War that began shortly thereafter, a vast nuclear arms race between the United States and the Soviet Union came into being. The United States conducted its first nuclear weapon test in July of 1945 and carried out two nuclear weapon attacks on the cities of Hiroshima and Nagasaki in Japan in August 1945, shortly before the end of the war. The Soviet Union carried out its first nuclear weapon test in 1949.

The bomb used against Hiroshima had an explosive yield of 12.5 kilotons or 12,500 tons of TNT equivalent. This weapon completely devastated the city of Hiroshima, killing some 200,000 people out of a total population of approximately 330,000. But, with the first thermonuclear weapon test by the United States and the Soviet Union just a few years later, in the 1950s, nuclear weapon tests explosions reached the megaton range, equivalent to 1 million tons of TNT — roughly 1,000 times more powerful than the bomb that destroyed Hiroshima. During the Cold War, the United States built more than 70,000 nuclear weapons and the Soviet Union some 55,000; peak stockpile numbers at one time reached 32,500 weapons for the U.S. and around 45,000 for the Soviets. In the early 1970s, U.S. strategic nuclear weapons carried on U.S. missiles numbered some 5,800 deployed, representing around 4,100 megatons in explosive yield, the Soviet numbers being 2,100 representing 4,000 megatons (the Soviet nuclear weapons tended to be larger).

These are numbers that exceed all comprehension, whether military, political or just on the basis of rationality. They are enough to destroy the world many times over. There also was a perceived risk that these weapons might simply spread all over the world for several reasons. One is national prestige. Since the earliest days of the Cold War, at least among major states, what has distinguished Great Powers from lesser states was the possession of nuclear weapons. Another basis of the proliferation risk has been national security. Israel from the beginning was concerned about attack by the large Arab armies arrayed against it; Pakistan believed it needed to offset the Indian nuclear weapon capability; and North Korean officials have said more than once that its nuclear weapons protect it from attack by the United States.

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Ambassador Thomas Graham Jr. served for nearly three decades at the U.S. Arms Control and Disarmament Agency, including a decade and a half as general counsel as well as Acting Director of the agency for most of 1993. In 1993 he led the effort to establish a long-term moratorium on the conduct of nuclear weapons tests. From 1994 to 1996, he was a principal figure in the worldwide effort to successfully support the conclusion of the Comprehensive Test Ban Treaty negotiations. In 1994 President Clinton appointed Thomas Graham as his special representative for arms control, non-proliferation and disarmament, with the rank of Ambassador. From 1993 to 1995 Ambassador Graham led the successful U.S. government effort to indefinitely extend the Nuclear Non-Proliferation Treaty. He has taught at—among others—Stanford University, University of Virginia, Georgetown University, University of Washington and Oregon State University.


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