This article develops a mathematical modeling framework using fault trees and Poisson processes for analyzing the risks of inadvertent nuclear war from U.S. or Russian misinterpretation of false alarms in early warning systems, and for assessing the potential value of options to reduce the risks of inadvertent nuclear war. The model also uses publicly available information on early warning systems, near-miss incidents, and other factors to estimate probabilities of a U.S.-Russia crisis, the rates of false alarms, and the probabilities that leaders will launch missiles in response to a false alarm.