Special Operations Forces (SOF) are closely involved with many of the military's developments to maintain a high readiness force. SOF emphasizes proper training and education, high physical and mental fitness, and proper moral awareness. In that respect, performance enhancing supplements or drugs (PES/D) can make a major contribution and be a next step in military development. But what is the impact of such a step? Accepting or even experimenting with PES/Ds will have far-reaching effects and raises medical, legal, and above all, ethical concerns. In light of this, our research question is: Could conditions be met such that it is morally justifiable to allow Special Operations Forces to use performance-enhancing supplements or drugs to improve individual capabilities, develop greater resiliency, and expand the overall performance of SOF units and, if so, what are the implications? To answer this question, this thesis reviews scholarly literature on ethics and history of military's use of drugs, drug and supplement factsheets, and survey of SOF members who would be the potential test systems. We contend that there are ethically permissible uses for PES/Ds within the military, and by SOF, in particular. Moreover, our examination of a sampling of SOF attitudes toward such use likewise supports our conclusion. Based on our findings, we assess that the broader SOF community should be open and willing to engage in the research and testing necessary to see whether such a conclusion deserves to stand. To that end, the type of PES/Ds, the extent of their use, and the conditions under which they would be utilized need to be explored through more rigorous testingunder safe but realistic conditions. ; Approved for public release; distribution is unlimited. ; Major, Royal Netherlands Marine Corps ; Major, United States Armed Forces ; http://archive.org/details/themoralobligati1094555553