By Nancy Sherman

What it feels like to put on a military uniform, deploy, and come home is still not really part of the public conversation about war. Even in philosophy or ethics classes in which war is the topic and some of our students are themselves about to go to war or have just come home, the inward war soldiers wage is often kept outside the classroom. As teachers, we tend to view it as a soldier's private matter, not something to touch or probe, especially if we don't wear the uniform.

But what we miss in being afraid to talk about a soldier's emotions is that psychological anguish in war is also moral anguish. Soldiers wrestle with what they see and do in uniform, even when their conflicts don't rise to the level of acute psychological trauma. And they feel guilt and shame even when they do no wrong by war's best standards. Some are in anguish about having interrogated detainees not by torture, but the proper way, by slowly and deliberately building intimacy only in order to exploit it. Others feel shame for going to war with a sense of revenge or for feeling it well up when a sniper guns down their buddy and their own survival depends on the raw desire to "get back." They worry that their triumph in coming home alive is at the expense of buddies who didn't make it.

These feelings of guilt and shame are ubiquitous in war. They are not just responses to committing atrocities or war crimes. They are the feelings good soldiers bear, in part as testament to their moral humanity. And they are feelings critical to shaping soldiers' future lives as civilians.

We tend to worry about war desensitizing warriors, about soldiers getting used to killing and accepting how cheap life can be. That may happen to some. But it was not the prevalent theme I heard in the 40 interviews I conducted with soldiers who have fought in Iraq and Afghanistan (as well as Vietnam and World War II). They felt the tremendous weight of their actions and the consequences of those actions. Indeed, they often felt responsible even for what was far beyond their control. They were far more likely to say, "If only I hadn't ... " or "If only I could have ... " than "It wasn't my fault." To hold themselves accountable, in a way that extends beyond strict culpability, was their way of imposing moral order on the hell of war. It was their way of reinserting a sense of moral accountability in the use of lethal force. And it was a way of acknowledging that they were inescapably agents of war's carnage.

In virtually all my interviews, guilt was the elephant in the room. It was a hard feeling for soldiers to articulate, but it filled their thoughts. It took three forms. The first I dubbed "accident guilt." Some soldiers blamed themselves for mishaps in equipment that took the lives of their buddies or the lives of innocents, though there was no negligence or culpable ignorance for which they could be held morally or legally responsible.

In one wrenching case, the gun on a tank misfired, blowing off most of the face of a private who was standing guard nearby. The Army officer in charge reconstructed the scene for me, narrating every detail, the way a person who has relived the scene over and over does:

"It was as if an ice cream scoop just scooped out his face. ... He survived the initial blast, if you can believe it. We were in the medic tent with him. It was one of the most traumatic things I have ever seen in my entire life. To literally see someone's face completely scooped out, to see just the very bottom part of his jaw working. ... He couldn't see, couldn't hear, couldn't scream. ... I mean, he had no eyes, obviously. No face. I can only imagine the terror, the fear, the pain he was in. He obviously couldn't breathe because he had no nose or mouth to take in air. ... It was one of the few times in my life I've really cried—tears just streaming down my face because I'm watching 10 people work over this kid. ... It was an unbelievable thing to see. ... It is one of those images that will be in your head until you die."

He then turned to his feelings of responsibility: "I'm the one who placed the vehicles; I'm the one who set the security. [As with] most accidents, I'm not in jail right now. ... I wasn't egregiously responsible. ... Any one of a dozen decisions made over the course of a two-month period and none of them really occurs to you at the time. Any one of those made differently may have saved his life. So I dealt with and still deal with the guilt of having cost him his life essentially. ... There's probably not a day that goes by that I don't think about it, at least fleetingly."

In the philosophical literature, many have rushed to call this kind of feeling "agent-regret," as the moral philosopher Bernard Williams labeled it, referring to the idea that one is "causally" implicated though not morally responsible "in virtue of something one intentionally did." But regret doesn't begin to capture what the soldier I talked with feels. It doesn't capture the despair or depth of the feeling—the awful weight of self-indictment and the need to make moral repair in order to be allowed back into a community in which he feels he has somehow jeopardized his standing. When he says he doesn't hold himself as "egregiously responsible," he means that he knows he didn't commit a careless blunder. But he still doesn't think of himself as fully, morally cleared.

Others I spoke with experienced "luck guilt," a generalized form of "survivor guilt." Marines I interviewed in Annapolis, shortly after their return from Baghdad, anguished about their undeserved luck at being in the scenic sailboat setting of the Naval Academy, far away from their brothers and sisters still at war. Soldiers I spoke with at Walter Reed Army Medical Center, themselves severely wounded, felt guilty for not suffering more, or as visibly, with limb loss or facial disfigurement. They felt that their relative good luck was a betrayal of those who were injured more severely.

What they felt, at bottom, was deep, empathic distress of the sort Melanie Klein, the British object-relations psychoanalyst, wrote about—a guilt felt for the injury and harm of others that is inseparable from empathic love. (As Klein understands it, we preserve as residue from early childhood the anxiety that we have hurt and persecuted—even physically damaged—the very objects that we depend upon for sustenance and love.)

In their own eyes, these soldiers felt that they had failed to take care of their buddies; they had broken a bond of solidarity and, even worse, failed to honor the duty of fidelity that enabled them to fight in the first place. One marine in Annapolis said that he was ready to go back to Afghanistan and that he was preparing his new wife for that reality: "You've got to prepare yourself for this because after sitting here in Annapolis for three years, after wonderful air conditioning in Annapolis, while my brothers and sisters have been out on their second and third tours."

As I listened to him, my thoughts wandered to another young officer, Siegfried Sassoon, the British World War I officer and poet. Against the wishes of his doctor, the eminent psychiatrist and anthropologist Capt. W.H.R. Rivers, Sassoon returned to the trenches out of a profound mix of love and guilt, as well as a sense of futility about his own protests against the war (inspired by meetings with Bertrand Russell). What he felt, separated from his troops, was nothing less than abandonment and banishment. To return to the front line might well be a kind of "death," he wrote in his memoirs, but it was also "my only chance of peace." In his poem "Banishment," he wrote, "Love drives me back to grope with them through hell." Another poem, "Sick Leave," concludes with the noiseless dead whispering to Sassoon, "When are you going out to them again? Are they not still your brothers through our blood?"

The most troubling kind of guilt I heard about had to do with accidental or unintended killing of innocents—what I call "collateral-damage guilt." One marine colonel who commanded a battalion just south of Baghdad during Operation Iraqi Freedom II told me how emotionally devastated his marines became when Iraqi children were injured or killed after cars ran the trigger lines at vehicle checkpoints. If the injuries or deaths were of adult men who they suspected were suicide bombers or women who might be concealing explosives under their burkhas, his marines would "generally fluff it off and justify it to themselves, rightly or wrongly." But when children were involved, "there was a dramatic psychological difference." In the case of a badly hurt child, "they would go out of their way to try calling in medevac aircraft to get the kid out to the hospital," sometimes putting themselves and one another at risk. They couldn't shake what they had done or justify the killing to themselves.

It is worth thinking about this in terms of the troops currently in Afghanistan. They are under far more restrictive rules of engagement than the marines in Iraq were. The U.S. commanding general in Afghanistan, Stanley A. McChrystal, has made it clear that the preponderance of risk is to be on the troops, not on civilians. That is not just one commander's rule; it is a cornerstone of just-war theory. Soldiers are trained and armed to take risks. Their job is to protect those who are not so trained. It is not enough for harm to civilians to be unintended, even if foreseen. Avishai Margalit and Michael Walzer have reformulated the point made some 30 years ago by Walzer in his book Just and Unjust Wars—then in the context of Vietnam, and restated now in the context of Israel's war in Gaza: Soldiers must "intend not to kill civilians, and that active intention can be made manifest only through the risks the soldiers themselves accept in order to reduce the risks to civilians."

Still, it is not easy to accept restrictions on firepower when insurgents exploit them by fighting without uniforms and shielding themselves in civilian populations. As some U.S. soldiers have complained, the new rules require us to fight "with one arm tied behind our backs." It is even harder to accept the restrictions when American lives are risked to win the hearts and minds of a population whose army may not itself be sharing adequately in the fight.

But the rules are also in place to protect the hearts and minds of our own troops. U.S. marines and soldiers in Afghanistan are fighters, but also cops and community organizers, charged with building moral and civic order "in a box." To fail to do that—or at least to seem to fail—in the face of a helpless child, not much younger than the boy warriors they are themselves, or, for more senior troops, a child who could be their own, is morally devastating. The image of that child's face haunts a soldier for a lifetime. And he may feel unrelenting guilt, however irrationally.

Nietzsche is the modern philosopher who understands that guilt so well: "Bad conscience" can become "torture without end," undoing any prospects for happiness. This subjective guilt, he says, doesn't grow in the soil where you would most expect it, such as in prisons where there are actually "guilty" parties who should feel remorse for wrongdoing. Rather it is often a "question of someone who ... caused harm," who causes a misfortune for which she is not really responsible.

Nietzsche appeals here to the earlier philosopher Spinoza for support, who wrote: The "bite of conscience" has to do with an "offense" where "something has gone unexpectedly wrong"; it is not really a case of "I ought not to have done that." Freud famously elaborates upon the theme: Enduring the recriminations of a harsh superego ("a bad conscience") is the cost of civilization. Essentially these moderns document what ancients, like Seneca in De Ira, warned long ago about outward-facing rage. The fury of revenge can leave its possessor more tormented than satisfied. So too the fury of self-directed anger.

We might think that Kant, too, would have much to say about the anguish of inner struggles of conscience. After all, Kant formalizes Socrates' dictum to "know thyself" into "the first command of all duties to oneself"—a highest-order duty to "scrutinize and fathom" one's heart. The spotlight is on me, on what I have done or failed to do, and not on others. The categorical imperative, the formula of the moral law for humans, is a stance of self-judgment.

But despite his first-person stance, Kant does not stress in this moral phenomenology the bite of bad feelings. The absence is deliberate. Kant's focus is on the mature conscience, and the attitude of that conscience is not punitive pain or fear but respect or reverence in the sense of attention and submission to our own authority as moral legislator. The idealized emotion we feel before genuine moral authority is dignified, not cowering. Indeed when the subject of repentance comes up, Kant warns against a morality that is "cheerless, morose, and surly," a self-punishment that becomes "self-torture." Beware of "hypocritical self-loathing" and the moral melancholy that detracts from the real work of morality, Kant intones, in a clear reaction against his Pietist upbringing. True virtue ought to be cheerful and soar with the sublimity of reverence for its law.

But Kant doesn't appreciate the fact that harsh self-judgment is not necessarily self-loathing or self-righteousness. It can be inseparable from empathy for those we harm and a sense of responsibility and duty—the desire to make reparations—even when the harm is unintentional, or intentional and warranted but no less loathed, as in "just" killing in war. That self-judgment and sense of responsibility, even guilt, may even be redemptive, a way of reconnecting with one's full humanity. The soldiers I spoke with longed for a way to feel whole, even if at the cost of their profound and acute feelings of guilt.

Montaigne famously warns about the high price of trying to stay whole. His own advice is often of moral insulation and compartmentalization: "The Mayor and Montaigne have always been separate," he boasts. "I know some who transubstantiate and metamorphose themselves into as many new beings and forms as the dignities which they assume: they are prelates down to their guts and livers and uphold their offices on their lavatory-seat. I cannot make them see the difference between hats doffed to them and those doffed to their commissions, their retinue, or their mule."

The message applies to some moments of wearing the uniform. It is the uniform one salutes, not the person in it. Erving Goffman, the great sociologist of roles, writes powerfully about the "language and mask" of social interaction. Soldiers, more than others, inhabit a world of public ritual and demeanor. To walk on a base, stateside, is to take note of that world—the spit-polish shoes, the creased uniforms, the stolid demeanor and gaze, the stiff salute, the parades, the "yes, ma'am" and "yes, sir." Even in death, there are the official photos that become the public faces of the fallen.

But soldiering, and especially wartime soldiering, is never about just a uniform or outward decorum. It is about the internal change that goes with putting on the uniform and deploying. That requires a conversion, of the kind William James describes in The Varieties of Religious Experience. James is not talking about a prophetic encounter or a born-again moment. He has in mind a more ordinary kind of metamorphosis, in which the focus of life shifts and a new organizing principle takes hold. It is, as he put it, a "recrystallizing" of "central parts of consciousness," a shifting of habit and attitude.

The point is that in putting on a uniform and going to war, a soldier grows skin that he does not shed lightly. And even when it is time to slough that skin, after years of service, it does not come off easily.

And yet, what moved me as I listened to soldiers, especially those recently returned, is how desperately they wanted to feel their old civilian selves. Or at least, they wanted to feel more-porous boundaries between being a soldier and a civilian—whether as a parent, a child, or a colleague in the work force; keeping their different selves fully separate was just too numbing. "We're taught to suck it up and truck on," a former Army major told me. "I'm tired of being stoic." The image of the sergeant in The Hurt Locker, numbed when he returns home, was not one they wanted for themselves: They wanted to come home to a spouse and child and know that they could reciprocate their love. In that regard, even the awful guilt and shame they felt for doing well what war requires was a way of being alive to a fuller self.

To bear the feelings of war, and to share them in their stories, was a start at making those feelings not just their private burdens. We in the teaching profession, on campuses where the military/civilian gap still yawns far too wide, have an obligation to help our students understand what soldiers go through and what our responsibility as citizens is to those whom we send to war. We owe soldiers not just public respect, but private respect. One way to give that respect is by understanding, empathically, the moral weight of war that they carry.

Nancy Sherman is a professor of philosophy at Georgetown University. She is author, most recently, of "The Untold War: Inside the Hearts, Minds, and Souls of Our Soldiers," just published by W.W. Norton.