The United States Department of Defense has, for at least 20 years, held the stated intention to enhance active military personnel ("warfighters"). This intention has become more acute in the face of dropping recruitment, an aging fighting force, and emerging strategic challenges. However, developing and testing enhancements is clouded by the ethically contested status of enhancements, the long history of abuse by military medical researchers, and new legislation in the guise of "health security" that has enabled the Department of Defense to apply medical interventions without appropriate oversight. This paper aims to reconcile existing legal and regulatory frameworks on military biomedical research with ethical concerns about military enhancements. In what follows, we first outline one justification for military enhancements. The authors then briefly address existing definitional issues over what constitutes enhancement before addressing existing research ethics regulations governing military biomedical research. Next, they argue that two common justifications for rapid military innovation in science and technology, including enhancement, fail. These justifications are (a) to satisfy a compelling military need and (b) strategic dominance. The authors then turn to an objection that turns on the idea that we need not have these justifications if warfighters are willing to adopt enhancement, and argue that laissez-faire approaches to enhancement fail in the context of the military due to pressing and historically significant concerns about coercion and exploitation. The paper concludes with what is referred to as the "least-worst" justification: Given the rise of untested enhancements in civilian and military life, we have good reason to validate potential enhancements even if they do not satisfy reasons (a) or (b) above.