How do we justify research into enhanced warfighters?

State militaries have strong interests in developing enhanced warfighters: taking otherwise healthy service personnel (soldiers, marines, pilots, etc.) and pushing their biological, physiological, and cognitive capacities beyond their individual statistical or baseline norm. However, the ethical and regulatory challenges of justifying research into these kinds of interventions to demonstrate the efficacy and safety of enhancements in the military has not been well explored. In this paper, we offer, in the context of the US Common Rule and Institutional Review Board framework, potential justifications for justifying research into enhancing warfighters on the grounds of (i) individual and group risk reduction; (ii) protection of third parties such as civilians; and (iii) military effectiveness.