Much of the commentary surrounding the 20th anniversary of the September 11th terrorist attacks coalesced into broad themes of sorrow and rage. Both emotions were appropriate to the day. The aptness of the grief is obvious. On that September morning two decades past, so many were lost in so many terrible ways. It was a heartbreaking day, compounded by waves of deepening confusion, terror, and the harrowing peril of our sudden cognizance of vulnerability.

Mixed in with the memorial reflections were recollections of the domestic and international unity experienced in the wake of the attacks. Much of the world drew together—people of good will across the globe proclaimed themselves Americans or New Yorkers or offered other tokens of solidarity. From Manhattan to Gander to the dusty streets of backwater Turkey where random passersby would stop me to express their grief and friendship—one withered old woman in a fantastically gaudy salvar rubbing my shoulder and proclaiming that all would be well—concord abounded, strangers became neighbors.

There was rage too, and it too helped reify the unity. In the day after the attack, Lance Morrow made a famous—some say infamous—case for it. He suggested the grief counselors stand aside for the moment and for no healing balms to be applied. “We shouldn’t feel better,” he insisted. “What’s needed is a unified, unifying, Pearl Harbor sort of purple American fury.”

On the anniversary day this weekend, both grief and rage were present again. Some simply percolated up from deep wells of emotion that had never dried out, called up again by the memorial words and images. Yet old rage and grief was augmented by new, bred over the course of our ignominious withdrawal from Afghanistan.

In the midst of the cavalcade of emotions these last several days, a familiar pattern reemerged. No one, of course, challenges the grief that attends the commemoration of the September 11 attacks. Many however, including especially many Christians, are terribly bothered by the rage. We needn’t be. Indeed, we mustn’t be. As I wrote sometime back:

Rage matters. I am not talking here about a directionless passion lashing out without scruples and destroying everything within reach. There is a rage, a white-hot indignation, which … is ignited by, directed toward, and proportionately reactive to a profoundly disordering injustice.

What I meant by this is that rage, in specific circumstances, can be proved appropriate, in part, because it is rational. Following Augustine, my much-missed doctoral supervisor Jean Bethke Elshtain regarded emotions as mode of thought, embodied thought, that bore epistemological significance—helping to alert us to truths we might apprehend tacitly but, as yet, have been unable to articulate. She understood we must not end with emotions, but neither ought we to discount them. We need to pay attention to what we find “offensive,” “repulsive, “and distasteful” for it might signal to us that something really fundamental has been violated.

Rage, as I say in self-quote above, is reactive to an already existing injustice. Because even rightly placed anger can manifest in disproportionate and indiscriminate actions, it needs to be disciplined. The just war tradition is the chief way that Christian moral theology has constrained rage—both in a negative sense by prohibiting certain kinds of actions as well as in the positive mode of obligating certain kinds of action. Just war is both a leash and a goad. In its primary function, it tells us when a particular injustice is grave enough that we ought to give full expression—that’s to say retributive force—to our anger in the face of it if, in the last resort, nothing else will sufficiently protect the innocent, requite an injustice, or punish evil. Not everyone agrees with this.

In a panel discussion at the National Press Club a few weeks after the September 11th attacks, the ethicist and pacifist Stanley Hauerwas endorsed the view that just war thinking developed as an exception to the general principle of Christian non-violence. “Why would you even have to come up with a justification for violence,” he observed, “if, as a matter of fact, you [didn’t] assume… the priority of non-violence on the part of these people?” Hauerwas, staying true to form, then went on to wonder why believers don’t press the advantage and craft exceptions to other normative commitments, “I mean,” he mused, “Christians don’t develop theories of Just Adultery.”

As to why Christians haven’t developed a theory of just adultery, first, and beside-the-point, I’m not sure some haven’t. But the main thing here is that Hauerwas’ silly quip shows him to be in line with the contemporary Catholic assertion that just war begins with a presumption against war—an assertion first appearing in the 1983 pastoral letter The Challenge of Peace and which misunderstands war in a number of importance ways. By conflating “adultery” with “war” Hauerwas presupposes both to be morally corrupt from the start. But he’s jumping the gun. To designate a particular sexual act “adultery” conveys the judgement that the act is illicit, distinguishing it from amorous romps that aren’t. The term “war” does not have a similar judgment built into it—that’s the whole premise of the idea of “just war” in the first place. It presupposes that there are just and unjust wars. So Hauerwas should have paired “war” not with “adultery” but simply with “sex.” The slogan “make love not war” should be understood as presenting options, not opposites.

But Hauerwas intends “war” to be a term already freighted with judgment. He compares the just warrior to a Christian penitent preparing himself for the Eucharist. Imagine, he encourages us, a penitent who, before receiving the sacrament, wishes his fellow believers the peace of Christ but says, “except”—as in “except to you, and to you.” Christian just warriors, Hauerwas completes the analogy repugnantly, are Christians who “cross their fingers” when they pass the peace of Christ to their neighbors.

Hauerwas, like the Catholic bishops on this point, simply gets war wrong. The just war tradition does not begin with a presumption against war. Rather, it carries a presumption against injustice, or, positively, a presumption for justice. When an injustice is brought into view, the just war framework helps us to assess whether the injustice is grave and intractable enough to warrant the deployment of force. In this, we mustn’t miss a latent fact—the just war tradition is a backward-looking ethic. It looks at injustices already in existence. Because of this, just warriors do not “cross their fingers” and deny the peace of Christ to anyone. Peace has already been broken by the aggressors. Jean Elshtain was on the panel with Hauerwas at the Press Club and beat up on him on this point. We pass the peace in a church, she pointed out, in part because we are surrounded by those who share our core commitments and with whom we enjoy concord. Such concord is not shared by those who drove our planes into our buildings. And because this broken peace shatters innocent lives, it is incumbent upon people of goodwill to strive to restore that peace.

But from the attacks of 2001 onward, clear into the present hour, there have always been Christians who loudly align with Hauerwas, arguing that no one—least of all the United States—is in a “position to throw stones or bombs” because everybody has sinned. Our rage, they assert, is misplaced because we have no grounds to judge others.

At least there is a certain consistency to all this. Many of the same Christians who align with Hauerwas are equally allergic to the notion of a God who judges. God is too often purged of anything we find uncomfortable. But a lot rides on our reaffirming the idea of Divine judgment. God’s moral perfection is scuttled if he does not judge—or care about the difference—between good and evil. And because we are called to be children of God—or bear the characteristics of our Father—we too are called to judge.

The just war application of this vocation is essential as we recall the events of 9-11. In the extraordinary new book, The Good Kill, the author  asserts that the punitive judgment that catalyzes the just war is indispensable to humanity. Why precisely? In part because carrying out deserved punishments furnishes society with protection through the restoration of just order— not simply physical protection, though that’s important, but moral protection as well. Society is justly ordered when everyone receives his or her due. Criminal activity assaults this order by taking from others their due: whether life, freedom, peace, or possessions. As James Turner Johnson writes, “From my perspective, shaped by thinking of morality and war in just war terms, egregious violations of the rights of people caught up in a conflict constitute an injustice that it is immoral not to seek to remedy.” Care, naturally, must be taken so that retribution is not confused with revenge, both of which are guided by different motives.

More will be said on this, but the retributive impulse has as its primary source the virtue of indignation—of rage at things that it’s right to be angry about. Like war, anger can be just or unjust. As it is in the Divine, rage is virtuous when it is aimed at the right thing, in the right proportion, for the right reason, and with the right aim.

Looking again at that terrible day 20 years ago, as Lance Morrow observed, “Anyone who does not loathe the people who did these things, and the people who cheer them on, is too philosophical for decent company.” The just war tradition knows that there is an enmity that can be wholesome and wise, and which can spur proportionate and discriminate and rightly aimed violence that out of love for the innocent is willing to struggle to rescue them or, if not, to demonstrate their worth by bringing their killers to justice.