Paper presented; Grossman, D., On Killing II: The Psychological Cost of Learning to Kill, Presented to American Psychological Association, 108th Convention, Washington D.C., Aug. 4, 2000.

Article published; Grossman, D., "On Killing II: The psychological cost of learning to kill." International Journal of Emergency Mental Health, Summer 2001.

The Psychological Consequences of Killing: Perpetration-Induced Traumatic Stress


This presentation is based on:

  • My research into the experiences of veterans who have killed in combat (as related in my book, On Killing).

  • My experience as a law enforcement trainer and a trainer of mental health professionals (onsite in the aftermath of the shooting of 15 students and teachers in Jonesboro, Arkansas, and after several other major school shootings).


This presentation will cover:

  • The physiological and psychological responses to combat: recent law enforcement research that provides powerful insight into interpersonal combat as "the universal human phobia," powerful heart rate increases now documented as occurring in combat, and resultant physiological responses, including forebrain shutdown.

  • The existence of a resistance to killing that exists in the midbrain of most healthy members of most species, becoming ascendant when the forebrain shuts down in combat, and the impact of this resistance across the centuries and as it was documented in World War II.

  • How the military and law enforcement communities have learned to overcome the resistance to killing, primarily through operantly conditioned responses using killing simulators in training which were designated by B. F. Skinner as an "almost perfect example of operant conditioning," the resultant dramatic increase in participation in killing activities rising from 15 to 20 percent in World War II to around 95 percent in Vietnam, and the tragic cost that can result, and did result in Vietnam.

  • The price of this conditioning, and a detailed analysis of some of the factors in the etiology and treatment of post-traumatic stress disorder PTSD). 


The Universal Human Phobia

Today we know that, in most cases, fear of death or injury is not generally sufficient to manifest itself in a powerful post-traumatic response. Modern society pursues fear through roller coasters, action and horror movies, rock climbing, bungee jumping, and a hundred other legal and illegal means. Fear itself is seldom a cause of trauma in everyday peacetime existence, but facing close-range interpersonal aggression is a traumatizing experience of an entirely different magnitude (Grossman, 1996, 76).

The Diagnostic and Statistical Manual (DSM-IV) of the American Psychiatric Association affirms that PTSD “...may be especially severe or longer lasting when the stressor is of human design (e.g. torture, rape).” The DSM-III-R also notes that, “some stressors frequently cause the disorder (e.g. torture), and others produce it only occasionally (e.g. natural disasters or car accidents).” 

Thus, 400,000 Americans will die slow, hideous, horrible, preventable deaths this year, due to cigarettes, but that does not generally change their behavior. Yet the presence of just one serial rapist or one serial killer in a city can change the behavior of the entire city. Just the distant possibility of interpersonal confrontation distresses us more and influences our behavior more than the statistical certainty of a slow hideous death from cancer (Grossman, 1996, 77).

When I speak to audiences I like to ask them, “What is the difference between, (a) a tornado that tears your house apart and puts you and your family in the hospital, and (b) someone who comes into your house in the middle of the night, ransacks your house and pistol whips you and your family into the hospital?” And the answer from the audience is always that the one is an “act of God,” and the other is “personal.” And that is the point: it is personal. With emphasis on the word "person" as in "human" (DSM-III-R).

When snakes, heights, or darkness causes an intense fear reaction in an individual it is considered a phobia, a dysfunction, an abnormality. But it is very natural and normal to respond to an attacking, aggressive fellow human being with a phobic-scale response. This may well be “the universal human phobia.” More than anything else in life, it is the potential for intentional, overt, human confrontation that has the greatest ability to modify and influence the behavior of human beings (DSM-III-R).

What this means to us today is that much of the body of psychology and psychiatry, and the body of history in this field, all affirm that a soldier, police officer, or peacekeeper on the street is infinitely more effective at influencing behavior than any quantity of impersonal bombs in the air, no matter how “smart” those bombs may be. Anything else is simply wishful thinking. Psychologically, aerial and artillery bombardments are effective, but only in the front lines when they are combined with the threat of the physical attack which usually follows such bombardments.


This is why there were mass psychiatric casualties following World War I artillery bombardments, but World War II’s strategic bombing of population centers were surprisingly counterproductive in breaking the enemy's will. Such bombardments without an accompanying close-range assault, or at least the threat of such an assault, are ineffective and may even serve to inoculate the enemy and to stiffen his will and resolve. 


This is also why inserting combat units behind the enemy is infinitely more important and effective than even the most comprehensive bombardments behind the lines or attrition along his front. We saw this in the early years of the Korean War when the rate of psychiatric casualties was almost seven times higher than the average for World War II. Only after the war settled down, lines stabilized, and the threat of having enemy in rear areas decreased, did the average rate go down to that of World War II (Gabriel, 1986). Again, just the potential for close-up, inescapable, interpersonal confrontation is more effective and has greater impact on human behavior than the actual presence of inescapable, impersonal death and destruction (Grossman, 1996, 80-81).


(As an aside, I would like to note that this is why, as I presented in a paper to the U.S. Air Force, in Washington, D.C., in July 1998, “...with very, very few exceptions, distant punishment in the form of aerial bombing is: psychiatrically unsound, psychologically impotent, strategically counterproductive, morally bankrupt, and likely to soon be illegal.” I think you can imagine that I was not a popular guest at that particular party.) 

A Resistance to Killing

To truly understand the nature of aggression and violence on the battlefield we must first recognize that most participants in close combat are literally “frightened out of their wits.” Once the bullets start flying, and combatants slam head on into the “universal human phobia,” they stop thinking with the forebrain (that portion of the brain which makes us human) and start thinking with the midbrain (the primitive portion of our brain which is indistinguishable from that of an animal) (Grossman, 1996, VIII)

In conflict situations this primitive, midbrain processing can be observed in the existence of a powerful resistance to killing one’s own kind. Animals with antlers and horns slam together in a relatively harmless head-to-head fashion, and piranha fight their own kind with flicks of the tail, but against any other species these creatures unleash their horns and teeth without restraint. This is an essential survival mechanism which prevents a species from destroying itself during territorial and mating rituals (Grossman, 1996, 5-6). 

One major modern revelation in the field of military psychology is the observation that this resistance to killing one’s own species is also a key factor in human combat. Brigadier General S.L.A. Marshall first observed this during his work as the Official US Historian of the European Theater of Operations in World War II. Based on his post-combat interviews, Marshall concluded in his book, Men Against Fire, (1946, 1978), that only 15 to 20 percent of the individual riflemen in World War II fired their weapons at an exposed enemy soldier. Key weapons, such as a flame thrower, usually fired. Crew served weapons, such as a machine gun, almost always fired. And firing would increase greatly if a nearby leader demanded that the soldier fire. But, when left to their own devices, the great majority of individual combatants throughout history appear to have been unable or unwilling to kill (Grossman, 1996, 144, 153-155).

Marshall’s findings have been somewhat controversial. Faced with scholarly concern about a researcher’s methodology and conclusions, the scientific method involves replicating the research. In Marshall’s case, every available, parallel, scholarly study validates his basic findings. Ardant du Picq’s surveys of French officers in the 1860s and his observations on ancient battles (Battle Studies, 1946), Keegan and Holmes’ numerous accounts of ineffectual firing throughout history (Soldiers, 1985), Richard Holmes’ assessment of Argentine firing rates in the Falklands War (Acts of War, 1985), Paddy Griffith’s data on the extraordinarily low killing rate among Napoleonic and American Civil War regiments (Battle Tactics of the American Civil War, 1989), the British Army’s laser reenactments of historical battles, the FBI’s studies of non-firing rates among law enforcement officers in the 1950s and 1960s, and countless other individual and anecdotal observations, all confirm Marshall’s fundamental conclusion that human beings are not, by nature, killers. Indeed, from a psychological perspective, the history of warfare can be viewed as a series of successively more effective tactical and mechanical mechanisms to enable or force combatants to overcome their resistance to killing (Grossman, 1996, 3, 4, 15, 16, 22).


Overcoming the Resistance

By 1946 the US Army had accepted Marshall’s conclusions. The Human Resources Research Office of the US Army subsequently pioneered a revolution in combat training which eventually replaced firing at bullseye targets with deeply ingrained “conditioning” using realistic, man-shaped pop-up targets that fall when hit. This kind of powerful “operant conditioning” is the only technique which will reliably influence the primitive, midbrain processing of a frightened human being. Fire drills condition terrified school children to respond properly during a fire. Conditioning in flight simulators enables frightened pilots to respond reflexively to emergency situations. Similar application and perfection of basic conditioning techniques increased the rate of fire to approximately 55 percent in Korea and around a 95 percent in Vietnam (Grossman, 1996, XVIII, 35, 251). 


While serving as an assistant professor of psychology at the US Military Academy at West Point, I was told by my boss, Col. Johnston Beach, that the military’s marksmanship training program, with its pop-up targets and intricate reinforcement schedule, was identified by B. F. Skinner, during a visit to West Point, as an “almost perfect example of operant conditioning.”


Equally high rates of fire resulting from modern conditioning techniques can be seen in Holmes’ observation of British firing rates in the Falklands, and FBI data on law enforcement firing rates since the nationwide introduction of modern conditioning techniques in the late 1960s (Grossman, 1996, 178).


(I should note here that I outlined the above affirmation of Marshall’s research, and the US military’s successful mechanisms to bypass this resistance, in several peer reviewed encyclopedia entries, and in my peer reviewed entry on “Aggression and Violence” in the definitive Oxford Companion to American Military History published in the spring of 2000.)

PTSD and the Price of Conditioning

The extraordinarily high firing rate resulting from modern conditioning processes was a key factor in our ability to claim that we never lost a major engagement in Vietnam. But conditioning which overrides such a powerful, innate resistance has enormous potential for psychological backlash. Every warrior society has a “purification ritual” to help the returning warrior deal with his “blood guilt” and to reassure him that what he did in combat was “good”. In primitive tribes this generally involves ritual bathing, ritual separation (which serves as a cooling-off and “group therapy” session), and a ceremony embracing the warrior back into the tribe. Modern Western rituals traditionally involve long separation while marching or sailing home, parades, monuments, and the unconditional acceptance of society and family (Grossman, 1996, 252-272).


In Vietnam this purification ritual was turned on its head. The returning American veteran was attacked and condemned in an unprecedented manner. The traditional horrors of combat were magnified by modern conditioning techniques, and this combined with societal condemnation to create a circumstance which resulted in .5 to 1.5 million cases of post-traumatic stress disorder (PTSD) in Vietnam veterans. This mass incidence of psychiatric disorders among Vietnam veterans resulted in the “discovery” of PTSD, a condition which we now know has always occurred as a result of warfare, but never in this quantity (Grossman, 1996, 271, 273-280).


PTSD seldom results in violent criminal acts, and upon returning to society the recipient of modern military conditioning is statistically less likely to engage in violent crime than a non-veteran of the same age. The key safeguard in this process appears to be the deeply ingrained discipline which the soldier internalizes with his military training (Grossman, 1996, 180, 260, 261, 319, 344).


(As an important aside in this area, I should note that I was called as a consultant, and on standby as an expert witness for the US government, in the case against Timothy McVeigh in the Oklahoma City bombing. It appeared that the defense was going to claim that McVeigh’s military training and Gulf War experiences were “matters of mitigation” which could help explain his horrific crime, and I was able to refute this claim, drawing extensively from US Bureau of Justice Statistics information that demonstrated that the returning veteran is a superior member of society who is less likely to be incarcerated than a non-veteran of the same age and sex.)


However, with the advent of interactive “point-and-shoot” arcade and video games there is significant concern that society is aping military conditioning, but without the vital safeguard of discipline. There is strong evidence to indicate that the indiscriminate civilian application of combat conditioning techniques as entertainment may be a key factor in worldwide, skyrocketing violent crime rates, including a sevenfold increase in per capita aggravated assaults in America since 1956. Thus, the latest chapter in American military history may be occurring in our streets (Grossman, 1996, 60, 261, 302-305). 


Only Anxiety is Forbidden

So far we have observed that confronting interpersonal human aggression at close range is, perhaps, “the universal human phobia,” which can result in a greater degree of psychological trauma than any other possible human experience. But the greatest trauma may occur afterwards, as a result of the midbrain’s “hijacking” of the forebrain.

In an extreme fear situation the midbrain reaches up and takes hold of the forebrain. Afterwards there appears to be an immediate, neural “shortcut” to the midbrain which mobilizes the body for survival in response to any “cue” associated with the traumatic incident. Increased heart rate, respiration, perspiration and a host of other physiological responses will occur for even the slightest of reasons, and sometimes for no discernible reason whatsoever. This can be thought of as a powerful form of associative or Pavlovian conditioning in which a host of neutral stimuli have now become conditioned stimuli which will touch off a powerful, “one trial learning,” conditioned response in the autonomic nervous system.


Time can be a valuable survival mechanism. When our ancestors first heard a lion’s roar they had to think, if even for a millisecond, “Oh, so THAT is a lion, I’d better run.” Subsequently the processing of that stimulus (i.e., the lion’s roar) would bypass the forebrain and essentially go straight from ears to their feet, saving milliseconds and enhancing their survival in the process. Indeed, not just the lion’s roar, but the lion's smell, the nature of the terrain, that spot in the jungle, and that time of day might also all be processed. Subsequently, individuals might not even know what has set them off, but something caused anxiety, made the hair stand up on the back of their necks, and caused them to slink away quietly. Soldiers in combat soon learn (if they are lucky to survive long enough) to react reflexively to the earliest hint of the sound of incoming artillery, and even to distinguish between kinds of artillery and the variety of responses required for survival, all without ever engaging the forebrain.


But for those of us who do not live on a battlefield, or hunt in the jungle, and with the exception of minor experiences like hot stoves, the powerful associations involved in these “one-trial learning” experiences can be extraordinarily distressing. I would venture to claim that nothing distresses healthy human beings more than to think that they are losing control of their minds. The midbrain’s “hijacking,” “hardwiring,” or “bypassing” of the forebrain can subsequently result in erratic, uncontrollable physiological reactivity. Even under the best of conditions this can sometimes continue for up to a year after a traumatic situation. When this occurs victims can become greatly distressed by the sense that they are losing control of their minds. But the “best of conditions” seldom occur naturally. Usually the physiological reactivity that occurs will cause them to dread further incidents, because they “know what will happen.” Thus their fear and physiological reactivity become enmeshed in a vicious cycle, a self-fulfilling prophecy in which anxiety creates fear and that fear creates more anxiety and so on. Very quickly the individual begins to manifest a powerful PTSD response.


In an attempt to assert control, or to avoid this reactivity, victims will attempt to (as outlined in the DSM-IV): repress memories; avoid thoughts, places or activities that remind them of the incident; hypercontrol their emotions; limit their expressions of emotion and affection; and cease activities that once caused them emotional or physical pleasure. This intense effort to hypercontrol their own minds and to avoid this fearful physiological reactivity will result in sleep problems because what they deny in the day will confront them in their dreams. They will experience hypervigilance and exaggerated startle reactions. Their emotions, forbidden to trickle out in a steady flow, will come out in bursts of rage and anger.


But it doesn’t have to be this way. If, at the very beginning, we can teach the subject to control their autonomic, physiological arousal, then they can nip this whole process in the bud, stopping the vicious cycle of fear and anxiety before it consumes them. “But,” we say, “it is called an ‘autonomic’ response because it is ‘automatic.’” Yes, but the bridge between the somatic and autonomic nervous system is breathing, and an increasing body of research and law enforcement experience indicates that if we teach the victim to control their breathing then they can control their physiological arousal. (This is based on information and feedback gained from training over 20,000 law enforcement personnel in this technique over the last three years.) The breathing technique that is being taught to SWAT teams, police departments, Green Beret battalions, and other elite forces around the world (sometimes referred to as “autogenic breathing”) consists simply of a deep, belly breath: breath in for a four-count, hold for a four-count, breath out for a four-count, hold for a four-count, and repeat three times.


It is not original with me, but I have been teaching this to mental health practitioners, military, law enforcement, and to my psychology classes for over five years now. In one case a young student whom I had not seen for several years came up to me in the supermarket with a tale he was burning to tell. “I was in a traffic accident,” he said. “My car flipped over, and I was trapped in the car, with one leg broken and one lung crushed.”


“What did you do?” I asked.


"I began to panic,” he said. “And then I remembered what you taught us: ‘In, two, three, four; hold, two, three, four; out, two, three, four; hold, two, three, four’ and I began to calm down.”


“Then what?”


“What else could I do? I turned the radio on and waited for someone to come get me. And they did. They pried open the car and pulled me out and said that if I had panicked and tried to tear myself out I might have killed myself.”


In one clinical situation a police officer who was suffering from a heart attack sat in the intensive care unit and demonstrated to his doctor how he could cut his heart rate in half using this technique. Around the world this technique is being embraced by military and law enforcement organizations who find themselves using it and proving its utility immediately before and during the most extreme of all possible circumstances. And it is being used by mental health practitioners after a stressful circumstance to teach survivors to master their physiological response and thereby prevent PTSD.


In the aftermath of the March 1998 Jonesboro school shootings, I taught the technique to the mental health professionals and clergy who had gathered that first night. The plan was for me to conduct the initial inbriefing, establishing the cognitive foundations for what would follow, including training and rehearsing the breathing techniques. The survivors would be broken into small groups and work their way through their experiences, one by one. During the debriefing everything but anxiety is permitted. Laughter and tears came out, but as soon as individuals began to show anxiety, usually manifesting itself in hyperventilation, then they were made to stop and breathe. Thus the survivors of this terrible, tragic event were able to confront the memories and emotions, while working from the very beginning to "delink" them from any kind of physiological response.


The next day the mental health professionals, clergy, and teachers conducted debriefings with the children, using the same techniques and the same rules. The results were very good. You cannot truly measure success in such circumstances, but there were immediate, positive responses from counselors and subjects, and a host of anecdotal support for the technique and its application in this circumstance. In one case, a mother complained to a counselor that she was so anxious that she had not been able to sleep for two nights. The counselor reports that he had her do one cycle of autogenic breathing--three deep breaths--and her next response, to her amazement, was simply to yawn. Also, there have been no suicides associated with the Jonesboro shootings, although there have been many resulting from the Littleton, Colorado, school shootings and the Oklahoma City bombing. 


You Are Only as Sick as Your Secrets


If we understand that the “universal human phobia” is close-range, interpersonal aggression, and that we are systematically enabling our combatants to kill in combat, then we can also begin to understand that aggression from a human ‘enemy’ will result in a magnitude of trauma that is generally unlike anything else that a human being can encounter. If you have never experienced such a trauma, you are apt to try to place it in terms of your own experiences and traumas, but the reality is that this will be a fundamentally flawed exercise. 


Perhaps one of our greatest handicaps in attempting to identify with the victim of human aggression is the fact that we cannot help but be influenced by Hollywood. I like to ask my audiences or psychology classes, “All’s fair in...what?” And they always answer, “Love and war.” “That's right,” I respond. “You see there are two things that men will often lie about. They will lie about what happened on that date last night, and they will lie about what happened to them in combat. And therefore that means that what we think is happening in combat is actually based on 5,000 years of what?” And the answer is always, “Lies.”


Truly, Hollywood lies to us, and we cannot help but be influenced by these lies. There are a wide variety of profoundly distressing physiological and psychological responses to close-range interpersonal aggression. These include loss of bowel control, sensory gating, loss of fine and complex motor control, and memory loss. For example, in one major survey conducted during World War II, a quarter of all combat veterans admitted that they urinated and defecated in their pants in combat. (Those are the ones who would admit it. The actual number may be quite a bit higher.) Among those wounded defecation and urination are almost universal. But you never read about that in the books or see it in the movies, do you? Yet this is just the tip of the iceberg of deception and lies that we must confront when we begin to examine the impact of close-range interpersonal aggression. 


To fully comprehend what happens to an individual in such a circumstance we have to realize that sympathetic nervous system (SNS) activation has become completely ascendant, shutting down all parasympathetic processes such as digestion. Furthermore, and most importantly, a frightened or angry individual has a shutdown of the forebrain, resulting in a powerful midbrain, or mammalian brain ascendancy, which is purely and absolutely focused on one thing: survival. One result of this is that the midbrain (which is a relatively simple mechanism, incapable of denial or transference) says “Hey! Something very bad just happened, figure out what it is and don’t ever let it happen again!” Of course the midbrain does not speak to us in words, but rather in bursts of emotion, and those emotions are translated, all too often, into a sense that, “It is all my fault.” During the critical incident debriefings after the Jonesboro shootings, many of the survivors (including 11, 12, and 13-year-old children) said, at some point, “It was my fault.” And the ones who were best able to convince them that it was not their fault were the individuals who shared the experience with them.


Perhaps the most distressing response of all is the common, immediate, "survival instinct" reaction of intense relief after witnessing violent death, even the death of a loved one, which is often articulated as, “That could have been me!” or “Thank God it wasn’t me.” The midbrain can be mercilessly logical, and it is intent on survival. In order to be able to help someone else survive you must, generally, first survive yourself. It is like the passengers on an airplane, who, “In case of loss of cabin pressure,” must “...put your own oxygen mask on first and then assist any small children traveling with you.” In a mercilessly logical system you must acknowledge that in order to help your children survive you must, with few exceptions, first survive yourself. Of course, afterward, this initial, self-centered impulse can result in powerful guilt feelings if not addressed.


During the initial inbriefing for the teachers who survived the shootings in Jonesboro, I outlined to them: what would be happening, the moral obligation to participate, the need to “de-link” the memory of the event from anxiety, the breathing exercise that would help in this “delinking,” and some “miscellaneous” things that they needed to know up front. One of the things I addressed was the loss of bowel and bladder control, the memory loss, sensory gating, and visual narrowing (tunnel vision) that was very common and perfectly natural. Then I outlined the irrational acceptance of responsibility and the common human reaction of “Thank God it wasn’t me,” after witnessing violent death. After I told them this last item, this “Thank God it wasn’t me response,” and told them that it was a perfectly natural and common response, several of these teachers laid their heads in their arms and began to sob uncontrollably. They had experienced the intense relief of having their deepest, darkest secret laid out on the table, only to find out that everyone else had the same secret in common, and it was OK. They were perfectly normal. There was nothing wrong with them if they felt this way. 


Perhaps half of the essence of counseling is that you are only as sick as your secrets, and until we begin to address some of these secrets we will never truly be able to assist fully in the healing process. The other half of the essence of counseling may be that pain shared is pain divided. And the means by which this “sharing” can occur is in a group critical incident debriefing, shortly after the trauma, in which each individual works completely through what occurred and receives the acceptance, forgiveness and support of their fellow victims. 


Conclusion: An Application to PTSD Resulting from Killing

Thus we have seen that there is a powerful resistance to killing in most healthy human beings. We have also seen that military and law enforcement organizations around the world have initiated a powerful conditioning process, through military combat training, that has enabled combatants to bypass this resistance. An extraordinarily high firing rate resulted from this process among US troops in Vietnam, British troops in the Falklands, and among modern US law enforcement officers. 

But conditioning which overrides such a powerful, innate resistance has enormous potential for psychological backlash. It has been noted that every warrior society has a “purification ritual” to help the returning warrior deal with his “blood guilt” and to reassure him that what he did in combat was “good”. In primitive tribes this generally involves ritual bathing, ritual separation (which serves as a cooling-off and “group therapy” session), and a ceremony embracing the veteran back into the tribe. Modern Western rituals traditionally involve long separation while marching or sailing home, parades, monuments, and the unconditional acceptance of society and family. As was noted previously, in Vietnam this purification ritual was turned on its head, and America paid a tragic price, with anywhere from .5 to 1.5 million cases of PTSD occurring as a result of our conduct of that war. 


One vital, age old aspect of this “purification ritual”, can and has been, reintroduced since Vietnam and that is the “debriefing,” conducted every night around the campfire. The introduction of 24-hour combat for months on end in World War I created an environment in which it became impossible for the soldier to perpetuate this ancient, nightly ritual. Throughout the 20th Century the opportunity to conduct a daily processing of combat experiences disappeared from the battlefield. The group critical incident debriefing is not a new occurrence on the battlefield. The absence of this daily debriefing is what is new, and now we are reintroducing this ancient process, with a degree of systematic, scientific expertise that has never occurred before.


Today, there is a moral, medical and a legal obligation to conduct these group debriefings. These debriefings must include all of the individuals who were involved in the critical incident, or, if that is not possible, individuals who were involved in similar incidents. Any organization that sends individuals in harms way, and especially any organization that calls upon humans to participate in the psychologically toxic realm of interpersonal aggression (which is, perhaps, the “universal human phobia”), and does not subsequently conduct a critical incident debriefing is morally, medically, and legally negligent.


Furthermore, there must be an environment wherein there are no “secrets” to be kept, since the perpetrators may well be “only as sick as their secrets.” That means, to the utmost of our ability, we create an environment of transparency and accountability in which no atrocities or criminal acts can occur, since these are the ultimate “secrets” which often cannot be confessed and must be kept at all costs. Col. Greg Belenke, a psychiatrist and head of one of the combat stress teams in the Gulf War, has definitively stated that atrocities and criminal acts are one of the surest paths to PTSD. PTSD can be thought of as “the gift that keeps on giving,” since it impacts not just the perpetrators, but also their spouses and their children in the decades to come (Belenke, 1996).


Rachel MacNair, in her research, has found that: "The item, 'There were certain things I did in the military I can't tell anybody,' was a strong indicator of the perpetration groups in just about every way I looked at it. When I compared those who were directly involved in the killing of civilians or prisoners with those who witnessed that but were not directly involved, yet did kill in other contexts (presumably more in line with traditional combat), the two items that differentiated were that one and nightmares." (R.M. MacNair, personal communication, June 15, 2000).


This means that atrocities, the intentional killing of civilians and prisoners, must be systematically rooted out from our way of war, for the price of these acts is far, far too high to let them be tolerated even to the slightest, smallest degree. This means that we enter into an era of transparency and accountability in all aspects of our law enforcement, peacekeeping, and combat operations. This also says something about that those who are called upon by their society to “go in harm’s way,” to use deadly force, and to contend with interpersonal human aggression. These individuals require psychological support just as surely as they require logistical, communications and medical support. Thus, as our society enters into the Post-Cold War era, the fields of psychiatry and psychology have much to contribute to the continuing evolution of combat, and to the evolution of our civilization. 



  • American Psychiatric Association (1987). Diagnostic and Statistical Manual of Mental Disorders (3rd ed.). Revised. Washington, DC: Author.

  • American Psychiatric Association. (1994). Diagnostic and Statistical Manual of Mental Disorders (4th ed.). Washington, DC: Author.

  • Ardant du Picq, C. (1946). Battle studies. Harrisburg, PA: Telegraph Press.

  • Belenke, G. (1996). Presentation to U.S.M.C. and US Navy personnel, Camp Lejeune, NC.

  • Gabriel, R. A. (1986). Military psychiatry: a comparative perspective. New York: Greenport Press.

  • Gabriel, R. A. (1987). No more heroes: madness and psychiatry in war. New York: Hill and Wang.

  • Griffith, P. (1989). Battle Tactics of the American Civil War. Yale University Press.

  • Grossman, D. (1996). On Killing: The Psychological Cost of Learning to Kill in War and Society. New York: Little, Brown, and Company.

  • Grossman, D. (2000). "Aggression and violence." The Oxford companion to American Military History. New York: Oxford University Press. 

  • Holmes, R. (1985). Acts of war: the behavior or men in battle. New York: Free Press.

  • Keegan, J., and R. Holmes. (1985). Soldiers. London: Guild Publishing. Marshall, S.

  • Marshall, S.L.A. (1978). Men Against Fire. Gloucester, MA: Peter Smith