The MAD doctrine aims to make the intentional use of nukes in war unworkable, but in doing so makes their accidental use due to mishap, misunderstanding or miscommunication much more likely, and the more people that are party to the MAD doctrine the more likely accidents are.

You don’t need to look very hard to find examples of cases where billions of people would have been killed if not for people choosing to ignore doctrine even when the information they had at hand said that they should use their weapons