Abstract
Ethical concerns dog emerging technologies designed to enhance warfighter performance. Brain-computer interfaces, exoskeletons, and mind- or body-altering drugs raise fears about risky, invasive, and experimental medical procedures that offer armies physically and cognitively superior soldiers that will dictate and disrupt the course of future war. What counts as enhancement, however, has been subject to longstanding and passionate debate. This study aims to put an end to this dispute by employing a conjoint experimental design to survey a group of military and professional experts from across the world to explore how definitional perceptions of enhancement influence ethical acceptability. Two main findings emerge. First, we find that there already exists a broad agreement about what constitutes enhancement, and this consensus spans countries, discipline, political orientation, and age. Future policy may now be able to accommodate a definition of enhancement that is widely shared among members of the international community. Second, across the board, ethical acceptability diminishes as medical technologies aim for transhuman warfighting capabilities. Enhancement research and development for military purposes must navigate the conflicting ethical demands of medical experimentation and lawful war. Human enhancement is not morally unacceptable but ethically precarious, requiring regulation, oversight, and transparency.