Researchers at Sandia National Laboratories and the University of California, Berkeley used the wargame Tantalus to examine how deterrence influences cyber attack decisions. The study created a scenario in which one player threatened another with a nuclear response if a critical infrastructure attack were launched. Participants selected an initial action, received a deterrent threat, and could revise their plan before execution. Across 394 games involving 1,090 players, the team observed instances where a planned cyber operation was abandoned after a deterrent threat was presented. The findings indicate that cyber threats were as effective as kinetic threats in prompting a change of course, though players used deterrent threats less frequently against cyber operations than against conventional attacks. The authors note that while cyber operations can be deterred, states appear reluctant to employ deterrence signals, possibly because they view cyberspace primarily as an intelligence domain. The methodology demonstrates that wargaming can reveal decision‑making moments that are otherwise unobservable in real‑world security contexts. The authors recommend greater attention to deterrence within cyber strategy, emphasizing that undisclosed threats cannot affect an adversary’s calculus.