In our "post-truth" era of bots, trolls, and intemperate presidential tweets, popular social platforms like Twitter and Facebook provide a growing medium for manipulation of information directed to individuals, institutions, and global leaders. Targeted influence campaigns have been waged in at least forty-eight countries so far. We've entered an age where stability during an international crisis can be deliberately manipulated at greater speed, on a larger scale, and at a lower cost than at any previous time in history. The authors in this volume examine the current reality from a variety of angles, considering how digital misinformation might affect the likelihood of international conflict and how it might influence the perceptions and actions of leaders and their publics before and during a crisis. The authors sound the alarm about how social media fuels information overload and promotes "fast thinking" over deliberation, with potentially catastrophic results for nuclear powers in times of conflict. This volume is the culmination of two multidisciplinary workshops produced in partnership between the Stanley Center for Peace and Security, the Hoover Institution at Stanford University, and the Center for International Security and Cooperation.