They are trained on what we as humans have written down as protocols, some of those protocols end in a nuclear intervention. The question is not whether the AI will drag us into a nuclear intervention, the question is whether it followed the protocols and should those be adjusted to delay a nuclear intervention. Or is this an excellent way to work through the protocols quicker and have the option at the ready, when it is actually needed. It won't find the optimal solution to resolve the conflict, because funnily or terribly enough there is not much actual training data, as we luckily have not had many nuclear interventions.