The U.S. military's prevailing norms of professionalism exhibit three paradoxes that render the organization poorly suited to meet contemporary challenges to its nonpartisan ethic, and that undermine its relations with civilian leaders. These norms, based on Samuel Huntington's objective civilian control model, argue that the military should operate in a sphere separate from the civilian domain of policymaking and decisions about the use of force. The first paradox is that Huntingtonian norms, though intended to prevent partisan and political behavior by military personnel, can also enable these activities. Second, the norms promote civilian leaders’ authority in decisionmaking related to the use of force, yet undermine their practical control and oversight of military activity. Third, they contribute to the military's operational and tactical effectiveness, while corroding the United States’ strategic effectiveness in armed conflict. These tensions in Huntington's norms matter today because of intensifying partisanship in society and in the military, the embrace by civilian leaders of objective control and their concomitant delegation of authority in armed conflict to the military, and growing questions about the causes of the inconclusive outcomes of the United States’ recent wars in Iraq and Afghanistan. It is time to develop a new framework for military professionalism.