In recent years, American military forces have been deployed in an ever-expanding array of humanitarian, peacekeeping, peacemaking, and nation-building operations. In practice American forces have often been reluctantly committed, and almost always with an extreme emphasis on force-protection and the avoidance of American casualties. Often this issue is discussed in the framework of perceived political constraints on American use of the military – in terms of how many casualties the American public will accept in exchange for a given mission. Beneath the level of the political constraints on American leaders, there lies a deeper tension having to do with the implicit moral contract between the United States and its military personnel. Although military personnel are required to follow all legal orders, morally the traditional contract between soldier and state rests on shared assumptions about the purposes for which national militaries will and will not be used.