May Christians ever endorse or participate in war or any form of military action? To that perennial question, Christians have generally given two answers: "No" or "Sometimes." The debate goes on not only between those two principled positions, but also between people who can't agree on whether the case at hand is one of those times or not.

Disagreement over the use of military force sparked a famous moment in the life of this magazine. Reinhold Niebuhr, who started his writing career with the Century, discontinued his association with the magazine because of its pacifist and noninterventionist leanings in the 1930s. This same dissatisfaction led Niebuhr to launch a new magazine, Christianity and Crisis, which called Christians to what he thought was a more realistic response to Hitler. Some of this history and some of the subsequent permutations of Niebuhrian realism are recalled in the review by Gary Dorrien (see page 652).

Niebuhr's quarrel was not actually with principled pacifists—those who embrace nonviolence as first and last a gospel witness. The principled pacifists are not worried, finally, about how history turns out; they leave the Hitlers and Milosevics of the world in God's hands, knowing that the triumph of good is an eschatological category.

What provoked Niebuhr most were those who touted nonviolence as an all-purpose strategy. People who adopted this stance, he thought, often minimized the power of evil, failed to discriminate between greater and lesser evils or between relative forms of justice, and encouraged a sentimental confidence in the short-term triumph of goodness.

This aspect of Niebuhr's critique remains relevant as the Kosovo crisis generates another round of debate over the moral use of force. Many of the religious voices that have condemned NATO's actions do not seem able to discriminate between greater and lesser evils, and they seem contemptuous of efforts to establish relative forms of justice. For example, a United Methodist bishop recently issued a call for peace in which he insisted there is no moral difference between NATO's bombing and Milosevic's ethnic cleansing. "Milosevic commits atrocities in Kosovo, so NATO commits atrocities in Serbia."

The bishop went on to analyze the Kosovo crisis by way of platitudes: "Violence will not defeat violence. Injustice will not cast out injustice. . . . It is time for peace." To this, Niebuhr would respond: Violence is never the ideal solution, but it may be part of the best solution we can find. And the most we can hope for in a fallen world is that one form of injustice will cast out a worse form of injustice.

What most rendered the bishop's appeal for peace religiously insipid, however, was the absence of an honest account of what a consistent nonviolent witness would look like—and what it would be prepared to leave in God's hands. If it would be better to let Milosevic permanently uproot the Kosovar Albanians rather than to take up arms, then the bishop should have the courage to say so.

Niebuhr never touted a Christian rationale for war, but he did believe, with Augustine, that love of neighbor might constrain one to prefer some grim and imperfect forms of peace and justice which, while far from ideal, are still better than the alternative. That's a position that still makes sense. And whatever position American Christians take on Kosovo, Niebuhr's call to realism should help keep them honest.