Immediately following the first and only uses of the atomic bomb in Hiroshima and Nagasaki, President Truman described nuclear stewardship as “an awful responsibility that has fallen to us.” The decision to use the bombs did clearly demonstrate the operational effectiveness of a new and awesome weapon, as the atomic bomb was generally accepted to have been critical in bringing about the Japanese surrender. Moreover, new weapon technologies have consistently been used in subsequent warfare throughout human history. Policy-makers in the post-1945 period, therefore, would have had to work energetically against that precedent if they sought to meet Truman’s “responsibility” and establish a tradition of non-use of nuclear weapons. This paper will defend the proposition that this is exactly what key American policy-makers sought and accomplished.

In the narrative that follows, the key dates to be examined are between 1945 and 1950—a transformative period in American foreign affairs when Paul Nitze and other key US policy-makers were setting the stage for the Cold War. The key to this study is not in episodically assessing why the United States repeatedly stepped back from the brink of the nuclear abyss, but rather in seeking to discern the development of a tradition of policy considerations concluding in the practice of nonuse. This policy evolution is tracked through three key debates of the early Cold War: establishing the uniqueness of nuclear weapons, creating the hydrogen bomb, and the writing of NSC-68.

Scholars have proposed two key explanations for the widely unexpected legacy of atomic weapons: the tradition of non-use and the nuclear taboo. The taboo explanation stems from a constructivist appreciation of the role of ideas and social action in state behavior, while the tradition of non-use comes from an assessment of the material and reputational factors considered by rational and strategically-oriented policy-makers. Both of these explanations need to be taken into account when assessing the non-use of nuclear weapons. Overall, I argue in this paper that US nuclear policy, with the early support of policy-makers like Paul Nitze, developed in a way that allowed for the emergence of a tradition of non-use of nuclear weapons. Evolving practices in the early years of the Cold War contributed substantially to a strategic commitment that helped prevent the use of nuclear weapons and prepare the ground for later struggles against proliferation.