The U.S. military has long relied upon technological superiority to ensure its dominance in conflict and to underwrite U.S. national security. In recent years, however, technology has both rapidly evolved and rapidly proliferated-largely as a result of advances in the commercial sector. This development has threatened to erode the United States' traditional sources of military advantage. The Department of Defense (DOD) has undertaken a number of initiatives to arrest this trend. This book provides an overview of selected emerging military technologies including: directed energy weapons; hypersonic weapons and lethal autonomous weapons.