The critical link between psychology and the military is important to recruiting, training, socializing, assigning, employing, deploying, motivating, rewarding, maintaining, managing, integrating, retaining, transitioning, supporting, counseling, and healing military members. These areas are hardly distinct, and The Oxford Handbook of Military Psychology has contents that cross these boundaries. Collectively, the topics covered in this book describe the myriad ways in which modern psychology influences warfare and vice versa. The extensive topics included come from within the areas of clinical, industrial/organizational, experimental, engineering, and social psychology. Articles address important areas in which the science and practice of psychology supports military personnel in their varied and complex missions. Among the topics addressed here are suitability for service, leadership, decision making, training, terrorism, socio-cultural competencies, diversity and cohesion, morale, quality-of-life, ethical challenges, and mental health and fitness. The focus is the ways in which psychology promotes the decisive human dimension of military effectiveness.