The advent of the Nuclear Age

The advent of the Nuclear Age marked a break in the world Harry S. Truman believed he understood. The atomic bomb helped bring relief to servicemen and their families by averting the prospect of a further invasion of Japan, but its arrival also raised a frightening possibility: that human beings had acquired the power to obliterate entire cities in an instant. For Truman, the bomb was at once a consequence of the war and a force that made the old assumptions about history and power inadequate.

A world remade by war

The nuclear age emerged within a wider upheaval. In the first months of Truman’s presidency, the United Nations was being launched, the Red Army remained a menacing presence in Eastern Europe, Britain was bankrupt, the Holocaust’s horrors had been revealed, and Berlin lay devastated. The war had also brought the atomic age into view in New Mexico and then at Hiroshima and Nagasaki. These developments were not separate from Truman’s sudden elevation to the presidency: the book presents his office, and its new and immense responsibilities, as among the war’s consequences.

Truman had long believed that human nature changed little over time and that the study of history could illuminate the present. He once expressed that faith in the observation, “The only new thing in the world is the history you don’t know.” Yet atomic power was precisely the kind of novelty that unsettled this confidence. The world had entered circumstances for which inherited rules seemed insufficient; Europe was in ruins, Asia was devastated and disordered, and the future of relations with Joseph Stalin remained uncertain.

Relief shadowed by dread

The news of the bomb brought many Americans a profound sense of reprieve, especially those with loved ones in uniform. Paul Fussell, then a lieutenant in France who had been scheduled to take part in an invasion of Japan despite serious wounds, later recalled the relief that he and other servicemen felt when they understood they would not have to assault the beaches near Tokyo. The expected invasion had threatened their lives; the bomb’s use appeared to release them from that immediate prospect.

That relief did not settle what the bomb meant. Americans with no direct experience of the fighting also remembered parents speaking apprehensively about the unknowable horror that had been unleashed. Newspaper commentary gave public form to the fear: the possibility that one bomb could destroy a whole city suggested not merely a new weapon, but a danger to civilization itself. Victory in the Pacific and anxiety about humanity’s future arrived together, without one cancelling the other.

Power and historical uncertainty

The book places this new danger within the extraordinary compression of Truman’s early presidency. In just three months, he faced decisions and international consequences of exceptional scale. The launching of the United Nations, the revelations of the Holocaust, the devastation of Europe, the Red Army’s presence in Eastern Europe, and the atomic bomb formed a single inheritance from the war, even as each demanded a different response.

Truman had grown up believing that individuals made history. But the scale of events now confronting him suggested forces larger than any one person. In a letter to his mother, he described the preceding days as a “dizzy whirl” in which he stood at the center, trying to act. The nuclear age thus appears not simply as a technological threshold, but as a test of judgment: immense power had become part of political life just as Truman was learning the reach and limits of his own responsibility.