Nope - M.A.D. principle assumes perfect rationality, i.e. all leaders with launch capability care about the survival of their subjects. This assumption worked well during the times of Cold War, but may fail in future, as more states gain access to nuclear technology and weaponry.

So I admit this principle has its limits of application, it's not perfect, but nevertheless it proved worthwhile tool to sustain global peace on the planet during Cold War era and up to this day. Imperfect tool, but only one that works.