This book examines the effects of Post Traumatic Stress Disorder (PTSD) on military leadership. For over twenty years, the United States Army has used the Be, Know, Do leadership model to describe what Army leadership is and does. Ongoing operations demonstrated shortcomings in current doctrine, which are clarified using recent leadership theories and historical experience. World War I, World War II, and Vietnam provide historical experiences that illustrate how American military leadership encountered PTSD, or one of its predecessors, on a large scale. A new epidemic of delayed stress response surfaced in the military, and leaders were once again left with an emerging problem during operations. Transformational, leader-member, and situational leadership theories can best augment the leadership model's shortfalls and address multi-leader collaboration towards PTSD, the relationship between the leader and follower with PTSD, and practice of leading social change within an organization comprised of PTSD diagnosed members.