Psychology is the science that will determine who wins and who loses the wars of the 21st century, just as physics ultimately led the United States to victory in World War II. Changes in the world's political landscape coupled with radical advances in the technology of war will greatly alter how militaries are formed, trained, and led. Leadership under fire--and the traits and skills it requires--is also changing. Grant, Lee, Pershing, Patton--these generals would not succeed in 21st century conflicts. In Head Strong: How Psychology is Revolutionizing War, Michael D. Matthews explores the many ways that psychology will make the difference for wars yet to come, from revolutionary advances in soldier selection and training to new ways of preparing soldiers to remain resilient in the face of horror and to engineering the super-soldier of the future. These advancements will ripple out to impact on the lives of all of us, not just soldiers. Amputees will have "intelligent" life-like prosthetics that simulate the feel and function of a real limb. Those exposed to trauma will have new and more effective remedies to prevent or treat post-traumatic stress disorder. And a revolution in training--based heavily in the military's increasing reliance on immersive simulations--will radically alter how police, fire, and first-responder personnel are trained in the future. The revised and expanded edition of Head Strong includes significant advances that have occurred in military psychology since its publication in 2013. Many of the predictions made in the first edition have come true, and exciting new developments in military psychology have emerged. The revised and expanded edition updates the existing chapters with important new developments, and adds new chapters on character and human performance optimization--both topics of significant interest in today's military. Authored by a West Point military psychologist, this book is one of the first to expose us to the smarter wars, and the world around them, to come.