Nuclear deterrence strategies are predicated on nuclear use scenarios. However, as nuclear weapons haven’t been used since 1945, why does use occur in scenarios but not in practice? If scenarios incorporated the political challenges of crossing the nuclear threshold, how would this change the utility of the deterrence strategies they support? To address these questions, this article examines Cold War-era American debates about a Soviet ‘first strike’, discusses the limits of technical critiques of nuclear use scenarios, and argues for an alternative approach to scenario design and criticism that includes political factors observable in crises and wars involving nuclear states.

How do emerging technologies affect nuclear stability? In this paper, we use a quasi-experimental cyber-nuclear wargame with 580 players to explore three hypotheses about emerging technologies and nuclear stability: (1) technological uncertainty leads to preemption and escalation; (2) technological uncertainty leads to restraint; and (3) technological certainty leads to escalation through aggressive counterforce campaigns. The wargames suggest that uncertainty and fear about cyber vulnerabilities create no immediate incentives for preemptive nuclear use. The greater danger to strategic stability lies in how overconfidence in cyber exploits incentivizes more aggressive counterforce campaigns and, secondarily, how vulnerabilities encourage predelegation or automation. Both of these effects suggest worrisome relationships between cyber exploits and inadvertent nuclear use on one hand and cyber vulnerabilities and accidental nuclear use on the other hand. Together, these findings reveal the complicated relationship between pathways to escalation and strategic stability, highlighting the role that confidence and perhaps-misplaced certainty—versus uncertainty and fear—play in strategic stability.