On Killing: The Psychological Cost of Learning to Kill in War and Society

by Dave Grossman

this school—and, to varying degrees, the U.S. Navy SEAL and Underwater Demolitions School, the U.S. Army Special Forces (Green Berets) and Airborne (paratrooper) courses, and U.S. Marine boot camp—are respected by soldiers around the world as individuals who can be trusted to maintain their cool in stressful situations.

“In war,” he wrote, “there is perhaps no general condition which is more likely to produce a large crop of nervous and mental disorders than a state of prolonged and great fatigue.” The four factors of (1) physiological arousal caused by the stress of existing in what is commonly understood as a continual fight-or-flight-arousal condition, (2) cumulative loss of sleep, (3) the reduction in caloric intake, and (4) the toll of the elements—such as rain, cold,

heat, and dark of night—assaulting the soldier all combine to form the “state of prolonged and great fatigue” that is the Weight of Exhaustion. Let us briefly review these factors.

Usually these two systems sustain a general balance between their demands upon the body’s resources, but during extremely stressful circumstances the fight-or-flight response kicks in and the sympathetic nervous system mobilizes all available energy for survival. In combat this very often results in nonessential activities such as digestion, bladder control, and sphincter control being completely shut down. This process is so intense that soldiers very often suffer stress diarrhea, and it is not at all uncommon for them to urinate and defecate in their pants as the body literally “blows its ballast” in an attempt to provide all the energy resources required to ensure its survival.

A soldier must pay a physiological price for an energizing process this intense. The price that the body pays is an equally powerful backlash when the neglected demands of the parasympathetic system return. This parasympathetic backlash occurs as soon as the danger and the excitement is over, and it takes the form of an incredibly powerful weariness and sleepiness on the part of the soldier.

Lack of Sleep

Lack of Food

Impact of the Elements

Strangely, such horrifying memories seem to have a much more profound effect on the combatant—the participant in battle—than the noncombatant, the correspondent, civilian, POW, or other passive observer of the battle zone. As we have seen, the combat soldier appears to feel a deep sense of responsibility and accountability for what he sees around him.

It is as though every enemy dead is a human being he has killed, and every friendly dead is a comrade for whom he was responsible. With every effort to reconcile these two responsibilities, more guilt is added to the horror that surrounds the soldier.

But facing aggression and hatred in our fellow citizens is an experience of an entirely different magnitude. All of us have had to face hostile aggression. On the playground as children, in the impoliteness of strangers, in the malicious gossip and comments of acquaintances, and in the animosity of peers and superiors in the workplace. In all of these instances everyone has known hostility and the stress it can cause. Most avoid confrontations at all costs, and to work ourselves up to an aggressive verbal action—let alone a physical confrontation—is extremely difficult.

It is not fear of death and injury from disease or accident but rather acts of personal depredation and domination by our fellow human beings that strike terror and loathing in our hearts.

This is one historical circumstance in which noncombatants did suffer a horrifyingly high incidence of psychiatric casualties and post-traumatic stress. Physical exhaustion is not the only or even the primary factor involved here. And neither is the horror of the death and destruction around them principally responsible for the psychic shock of this situation. The distinguishing characteristic here, as opposed to numerous other noncombatant circumstances marked by an absence of psychiatric casualties, is that those in concentration camps had to face aggression and death on a highly personal, face-to-face basis. Nazi Germany placed a remarkable concentration of aggressive psychopaths in charge of these camps, and

the lives of these victims were completely dominated by the personalities of these terrifyingly brutal individuals.

What maneuver warfare advocates have discovered is that over and over in history, civilians and soldiers have withstood the actuality of fear, horror, death, and destruction during artillery bombardments and aerial bombardments without losing their will to fight, while the mere threat of invasion and close-up interpersonal aggression has consistently turned whole populations into refugees fleeing in panic. This is why putting unfriendly troop units in the enemy’s rear is infinitely more important and effective than even the most comprehensive bombardments in his rear or attrition along his front. We saw this in the Korean War, in which, during the early years of the war, the rate of psychiatric casualties was almost seven times higher than the average rate for World War II. Only after the war settled down, lines stabilized, and the threat of having enemy in the rear areas decreased, did the average rate go down to slightly less than that of World War II. The potential of close-up, inescapable, interpersonal hatred and aggression is more effective

and has greater impact on the morale of the soldier than the presence of inescapable, impersonal death and destruction.

This is a very interesting theoretical concept, but what is important to us is to understand that this process of inoculation is exactly what occurs in boot camps and in every other military school worthy of its name. When raw recruits are faced with seemingly sadistic abuse and hardship (which they “escape” through weekend passes and, ultimately, graduation) they are—among many other things—being inoculated against the stresses of combat. Combining an understanding of (a) those factors that cause combat trauma with (b) an understanding of the inoculation process permits us to recognize that in most of these military schools the inoculation is specifically oriented toward hate.

I do not believe that military organizations have truly understood the nature of the Wind of Hate, or of the resultant need for this kind of inoculation. It is only since Seligman’s research that we have really had the foundation for a clinical understanding of these processes. However, through thousands of years of institutional memory and the harshest kind of survival-of-the-fittest evolution, this kind of inoculation has manifested itself in the traditions of the finest and most aggressive fighting units of many nations. By understanding the role of hate on the battlefield, we now can finally and truly understand the military value of what armies have done for so long and some of the processes by which they have enabled the soldier to physically and psychologically survive on the battlefield.

Many authorities speak and write of emotional stamina on the battlefield as a finite resource. I have termed this the Well of Fortitude. Faced with the soldier’s encounters with horror, guilt, fear, exhaustion, and hate, each man draws steadily from his own private reservoir of inner strength and fortitude until finally the well runs dry. And then he becomes just another statistic. I believe that this metaphor of the well is an excellent one for understanding why at least 98 percent of all soldiers in close combat will ultimately become psychiatric casualties.

This is why “fortitude,” rather than “courage,” is the proper word to describe what is occurring here. It is not just a reaction to fear, but rather a reaction to a host of stressors that suck the will and life out of a man and leave him clinically depressed. The opposite of courage is cowardice, but the opposite of fortitude is exhaustion. When the soldier’s well is dry, his very soul is dry, and, in Lord Moran’s words, “he had gazed upon the face of death too long until exhaustion had dried him up making him so much tinder, which a chance spark of fear might set alight.”

In Normandy during World War II Field Marshal Montgomery had two classes of divisions. Some were veterans of North Africa, and others were green units, without previous combat experience. Montgomery initially tended to rely on his veteran units (particularly during the disastrous Operation Goodwood), but these units performed poorly, while his green units performed well. In this instance, failing to understand the influence of emotional exhaustion and the Well of Fortitude had a significant negative impact on the Allied effort in World War II.

The soldier in combat is trapped within this tragic Catch-22. If he overcomes his resistance to killing and kills an enemy soldier in close combat, he will be forever burdened with blood guilt, and if he elects not to kill, then the blood guilt of his fallen comrades and the shame of his profession, nation, and cause lie upon him. He is damned if he does, and damned if he doesn’t.

Numerous studies have concluded that men in combat are usually motivated to fight not by ideology or hate or fear, but by group pressures and processes involving (1) regard for their comrades, (2) respect for their leaders, (3) concern for their own reputation with both, and (4) an urge to contribute to the success of the group.[5]

To a significant degree, the social barrier between officer and enlisted man, and between sergeant and private, exists to enable the superior to send his men into mortal danger and to shield him from the inevitable guilt associated with their deaths. For even the best leaders make some mistakes that will weigh forever upon their consciences. Just as any good coach can analyze his conduct of even a winning game and see where he could have done better, so does every good combat leader think, at some level, that if he had just done something different these men—these men he loved like sons and brothers—might not have died.

This is a deadly, dangerous line of thought for leaders, and the honors and decorations that are traditionally heaped upon military leaders at all levels are vitally important for their mental health in the years that follow. These decorations, medals, mentions in dispatches, and other forms of recognition represent a powerful affirmation from the leader’s society, telling him that he did well, he did the right thing, and no one blames him for the lives lost in doing his duty.

The dead soldier takes his misery with him, but the man who killed him must forever live and die with him. The lesson becomes increasingly clear: Killing is what war is all about, and killing in combat, by its very nature, causes deep wounds of pain and guilt. The language of war helps us to deny what war is really about, and in doing so it makes war more palatable.

Even the field of psychology seems to be ill prepared to address the guilt caused by war and the attendant moral issues. Peter Marin condemns the “inadequacy” of our psychological terminology in describing the magnitude and reality of the “pain of human conscience.” As a society, he says, we seem unable to deal with moral pain or guilt. Instead it is treated as a neurosis or a pathology, “something to escape rather than something to learn from, a disease rather than—as it may well be for the vets—an appropriate if painful response to the past.”

The link between distance and ease of aggression is not a new discovery. It has long been understood that there is a direct relationship between the empathic and physical proximity of the victim, and the resultant difficulty and trauma of the kill. This concept has fascinated and concerned soldiers, poets, philosophers, anthropologists, and psychologists alike.

Incredibly, yet undeniably, there is a qualitative distinction in the eyes of those who suffered: the survivors of Auschwitz were personally traumatized by criminals and suffered lifelong psychological damage from their experiences, whereas the survivors of Hamburg were incidental victims of an act of war and were able to put it behind them.

First, the closer the soldier draws to his enemy the harder it is to kill him, until at bayonet range it can be extremely difficult, and, second, the average human being has a strong resistance to piercing the body of another of his own kind with a handheld edged weapon, preferring to club or slash at the enemy.

A great deal of misunderstanding has arisen from the fact that a “bayonet charge” could be highly effective even without any bayonet actually touching an enemy soldier, let alone killing him. One hundred per cent of the casualties might be caused by musketry, yet the bayonet could still be the instrument of victory. This was because its purpose was not to kill soldiers but to disorganize regiments and win ground. It was the flourish of the bayonet and the determination in the eyes of its owner that on some occasions produced shock.

What these units (or at least their leaders) must understand is that actual skewering almost never happens; but the powerful human revulsion to the threat of such activity, when a soldier is confronted with superior posturing represented by a willingness or at least a reputation for participation in close-range killing, has a devastating effect upon the enemy’s morale.

It is when the bayonet charge has forced one side’s soldiers to turn their backs and flee that the killing truly begins, and at some visceral level the soldier intuitively understands this and is very, very frightened when he has to turn his back to the enemy. Griffith dwells on this fear: “Perhaps this fear of retreat [in the face of the enemy] was linked to a horror of turning one’s back on the threat…. A type of reverse ostrich syndrome may have applied, whereby the danger was bearable only while the men continued to watch it.” And in his superb study of the American Civil War, Griffith also notes many instances in which the most effective firing and killing occurred when the enemy had begun to flee the field.

The second factor that enables killing from behind is a process in which close proximity on the physical distance spectrum can be negated when the face cannot be seen. The essence of the whole physical distance spectrum may simply revolve around the degree to which the killer can see the face of the victim. There appears to be a kind of intuitive understanding of this process in our cultural image of back shooting and back stabbing as cowardly acts, and it seems that soldiers intuitively understand that when they turn their backs, they are more apt to be killed by the enemy.

As we will observe when we study the process by which the U.S. Army raised its firing rates from 15 to 20 percent in World War II to 90 to 95 percent in Vietnam, this procedure of precisely rehearsing and mimicking a killing action is an excellent way of ensuring that the individual is capable of performing the act in combat.

When man first picked up a club or a rock and killed his fellow man, he gained more than mechanical energy and mechanical leverage. He also gained psychological energy and psychological leverage

that was every bit as necessary in the killing process.

Dr. Stanley Milgram’s famous studies at Yale University on obedience and aggression found that in a controlled laboratory environment more than 65 percent of his subjects could be readily manipulated into inflicting a (seemingly) lethal electrical charge on a total stranger.

The mass needs, and we give it, leaders who have the firmness and decision of command proceeding from habit and an entire faith in their unquestionable right to command as established by tradition, law and society. —Ardant du Picq

They found that the individuals who had no combat experience assumed that “being fired upon” would be the critical factor in making them fire. However, veterans listed “being told to fire” as the most critical factor.

In Milgram’s experiments the demands of authority were represented by an individual with a clipboard and a white lab coat. This authority figure stood immediately behind the individual who was inflicting shocks and directed that he increase the voltage each time the victim answered a question incorrectly. When the authority figure was not personally present but called over a phone, the number of subjects who were willing to inflict the maximum shock dropped sharply. This process can be generalized to combat circumstances and “operationalized” into a number of subfactors: proximity of the authority figure, respect for the authority figure, intensity of the authority figure’s demands, and the authority figure’s legitimacy.

In the Greek phalanx the leader at squad and platoon level was a spear-carrying member of the masses. The primary function of these leaders (as defined by their equipment and lack of mobility within the formation) was to participate in the killing. The Roman formation, on the other hand, had a series of mobile, highly trained, and carefully selected leaders whose primary job was not to kill but to stand behind their men and demand that they kill. Many factors led to the military supremacy that permitted the Romans to conquer the world. For example, their volleys of cleverly designed javelins provided physical distance in the killing process, and their training enabled the individual to use the point and overcame the natural resistance to thrusting. But most authorities agree that a key factor was the degree of professionalism in their small-unit leaders, combined with a formation that facilitated the influence of these leaders.

But the price for the leader who has lived through such a situation is high. He must answer to the widows and the orphans of his men, and he must live forevermore with what he has done to those who entrusted their lives to his care. When I interview combatants, many tell of remorse and anguish that they have never told anyone of before. But I have not yet had any success at getting a leader to confront his emotions revolving around the soldiers who have died in combat as a result of his orders. In interviews, such men work around reservoirs of guilt and denial that appear to be buried too deeply to be tapped, and perhaps this is for the best.

Disintegration of a combat unit…usually occurs at the 50% casualty point, and is marked by increasing numbers of individuals refusing to kill in combat…. Motivation and will to kill the enemy has evaporated along with their peers and comrades.

A tremendous volume of research indicates that the primary factor that motivates a soldier to do the things that no sane man wants to do in combat (that is, killing and dying) is not the force of self-preservation but a powerful sense of accountability to his comrades on the battlefield.

Marshall noted that a single soldier falling back from a broken and retreating unit will be of little value if pressed into service in another unit. But if a pair of soldiers or the remnants of a squad or platoon are put to use, they can generally be counted upon to fight well. The difference in these two situations is the degree to which the soldiers have bonded or developed a sense of accountability to the small number of men they will be fighting with—which is distinctly different from the more generalized cohesion of the army as a whole. If the individual is bonded with his comrades, and if he is with “his” group, then the probability that the individual will participate in killing is significantly increased. But if those factors are absent, the probability that the individual will be an active participant in combat is quite low. Du Picq sums this matter up when he says, “Four brave men who do not know each other will not dare to attack a lion. Four less brave, but knowing each other well, sure of their reliability and consequently of mutual aid, will attack resolutely. There,” says du Picq, “is the science of the organization of armies in a nutshell.”

In addition to creating a sense of accountability, groups also enable killing through developing in their members a sense of anonymity that contributes further to violence.

Shalit points out that “such senseless violence in the animal world—as well as most of the violence in the human domain—is shown by groups rather than by individuals.”

All crowding has an intensifying effect. If aggression exists, it will become more so as a result of crowding; if joy exists, it will become intensified by the crowd. It has been shown by some studies…that a mirror in front of an aggressor tends to increase his aggression—if he was

disposed to be aggressive. However, if this individual were not so disposed, the effect of the mirror would be to further enhance his nonaggressive tendencies. The effect of the crowd seems to be much like a mirror, reflecting each individual’s behavior in those around him and thus intensifying the existing pattern of behavior.