Modern technological warfare requires a level of cognitive ability and discipline unique in the history of armed conflict. Recent advances in physiology, nutrition, neuroscience, and engineering offer a significant potential to prevent or reduce the degradation of a warfighterÕs mental or physical capabilities in this demanding environment. The authors explore four categories for potential enhancement of military personnel: genetic or computational-mechanical alteration of the human body; physiological monitoring and tighter coupling between man and machine; pharmaceuticals; and nutrition and supplementation. None of these types of enhancements is without controversy; in particular, genetic intervention would require morally intolerable experimentation. In the foreseeable future, the military enhancement technologies most likely to see use will be akin to those seen in elite athletics. Physiological monitoring and feedback, changes in nutrition, and careful pharmaceutical interventions all could improve warfighter performance, and, the authors assert, such enhancements are not morally problematic if their effects are candidly assessed and revealed. In choosing whether and how to enhance military personnel, the government must balance long-term health hazards with a reduced risk of near-term injury or death. If physiological monitoring and feedback (and regulation, through drugs or other means) can decrease large, immediate, or long-term risks to the life or well-being of service personnel, the authors write, there appears to be a moral obligation to provide those enhancements to warfighters.