It is a true pleasure to take part in this Perspectives exchange and to have a chance to engage with and learn from the excellent scholarship and insights of Jeffrey W. Taliaferro. This unique format provides a far more meaningful interaction than standard one-off reviews, and I am grateful to the journal, its editors, and especially Professor Taliaferro.

Reflecting both Taliaferro’s important new book and his thoughtful engagement with mine, I am once again struck by the complex and consequential choices faced by US statesman after World War II. The United States confronted a hostile, ruthless, ideological, and geopolitical foe in the Soviet Union. Europe and East Asia had been devastated by total war and were economically prostrate. In regions around the world, the often-messy process of decolonization and nation-building generated contested borders and bitter disputes. And perhaps most important of all, this chaos and uncertainty took place under the shadow of a fearsome new military technology that transformed the very nature of war: nuclear, then thermonuclear, weapons had the potential to wreak unthinkable devastation and havoc in hours, even minutes, and could be delivered from great distances, upending all previous strategic calculations.

How would US leaders respond to this new world? There was literally nothing in the political DNA of the United States—less than a decade removed from a deep isolationism whose characteristics were far closer to its historical habits than the war-time effort—that suggested that it would embrace such an extraordinary postwar grand strategy: to open the world economy and governance, to contain the Soviet threat, and to inhibit the spread of independent nuclear weapons programs. This interconnected grand strategy was steeped in controversy and did not arrive at all at once, was extremely difficult to achieve, involved trade-offs, and, as Taliaferro correctly points out, was often racked by internal contradictions. The tension between the containment and inhibition missions, for example, increased in the 1960s and 1970s, as the United States, weary from the Vietnam War, sought détente with the Soviet Union and accommodation with China while reducing its overseas commitments. Taliaferro’s Defending Frenemies expertly reveals how the United States wrestled with its desire to keep Israel, Pakistan, South Korea, and Taiwan non-nuclear—succeeding in two cases—without unduly sacrificing other geopolitical and regional objectives. This is all the more impressive because each of these states presented its own inhibition challenges, especially as each one’s security priorities were often at odds with how the United States saw the world.

One thing Taliaferro and my work shares is a dedication to careful historical reconstruction based on primary documents. There are many places where statistical methods provide great insight into political phenomena, but it is less clear what insight they provide when the relevant “Ns” are 9 (the number of nuclear states), 2 (the number of nuclear weapons detonated against another state), and, most importantly, 0 (the number of thermonuclear wars). In the end, perhaps these two reviews highlight something even more important—how historians and political scientists can apply the best practices of each of their disciplines to better understand one of the most pressing, consequential issues of our time.