How can MAD work in a world where submarines can fire nuclear weapons without being detected?
I just finished the book Nuclear War: A Scenario. It said it's impossible to detect submarines. But MAD rests on the premise that we know which country attacks us and will retaliate. If submarines attack a country, let's assume it's the US, and the US can't find out the country of the submarines. How can MAD work? If MAD doesn't work in this scenario, what deters a country from using nuclear weapons?