This project argues that the emerging moral principle of Responsibility to Protect (R2P) both extends and enriches the just war tradition of thought. Christian communities are uniquely positioned to bring the Christian tradition of just war thought to bear on global discussion of R2P and related policy debates over protection of human rights and dignity. R2P, meanwhile, sheds light on concerns for the well-being of marginalized people, and for the prevention of violence, which have deep roots in Christian theological and ethical thought. Placing R2P in mutual critique with the just war tradition can enhance and revitalize theological and ethical thought, among scholars and within Christian churches, on the role of political authorities in dealing with conflicts and the purpose of national borders in an increasingly connected world. Christians respect political authority as an ordering force in a fallen world, yet they are loyal to a source of life and moral norms infinitely higher than any worldly power. Thus, they understand that the legal and political structures extant in a given age can serve to promote human flourishing, but they draw on a set of norms which are theologically grounded and can serve to critique worldly power. This project encourages Christians to advocate for the poor and oppressed, including those whose human rights are most threatened in situations of violence, and to think creatively about how leaders at various levels of power and authority can work together to protect those who are oppressed, beginning with listening to oppressed people and respecting their agency. R2P provides for Christians a new way of thinking ethically, within church communities and in pluralistic contexts, about conflict and oppression. It also provides Christians an opportunity to continue to promote a theologically-informed vision of the good, through careful study of our long and rich tradition of thought on war.