AbstractExpanding the traditional question of how and why the bomb was built when it was, this paper asks how socio‐historical factors influenced the reception of the bomb in the West. It suggests that the bomb was received as the ‘winning weapon’ and that this view of it was linked to two historical factors: the Great Collapse, which undermined belief in historical progress and threatened the survival of the democracies; and the failure of balancing, the inability of the democracies, for a number of sociopolitical reasons, to act in their own collective security. As the winning weapon, the bomb was expected to overcome these problems. More broadly, the analysis suggests that when collective actions do not appear capable of redressing persistent threats, then leaders tend to invest their faith in technological pan