Professor Jeffrey Knopf, with the James Martin Center for Nonproliferation Studies at the Middlebury Institute of International Studies in California and with the Center on International Security and Cooperation at Stanford University explains why we can no longer rely only on deterrence, the nuclear taboo, arms control agreements and good luck. He argues that we must examine the psychological and societal aspects of maintaining nuclear peace. This is essential in a world of deeply entrenched nationalisms and autocratic leaders in many countries who can no longer be relied upon to be motivated by long-standing social norms that have contributed to keep nuclear peace for nearly 80 years.