Anyone seriously interested in applying traditional just war theory to current international affairs finds it difficult even to begin. Part of the problem is that the theory itself is badly misunderstood. Some people—proponents and detractors alike—think it is first and foremost a product of Christian theological wisdom and a repository of Christian principles having relevance to relations between states. A Catholic who points to recent popes, to John Courtney Murray, or to the tradition of Thomas Aquinas when evoking just war categories adds weight to this conception of just war theory. So too does a Protestant who goes to Martin Luther or Paul Ramsey for information about just war. It is true that just war doctrine was advanced and preserved by Christian theologians and canon lawyers. But these were not the only contributors to the tradition of just war thought, nor have they been the only important preservers of whatever wisdom it contains for limiting war.