War, Honor, and Human Nature

Moral Injury and the Warrior Ethos, an Evolutionary Perspective

For most of my career I have been concerned with two related questions. The first is how to build warriors and units who possess the skills, and culture, required to fight and win our nation’s wars. The second is how to prepare them psychologically and morally for what fighting actually entails.

When we began developing what eventually became the Modern Army Combatives Program in the 2nd Ranger Battalion, the focus was never simply on teaching soldiers how to fight. Skill was only part of the problem. Fighting also requires a mindset. Warriors must be able to function under stress, act decisively in violent situations, and remain disciplined in the use of force. That portion of the training carries over to every range of combat. A training system that develops technical ability but neglects the psychological and moral dimensions of combat is incomplete.

Within the 75th Ranger Regiment, excellence has never been an accident of talent alone. It is the product of a culture that consistently emphasizes small-unit competence, aggression, and the expectation that every Ranger must be prepared to close with and destroy the enemy. The Combatives Program was developed as one tool to reinforce that culture. It kept the focus of training on the individual Ranger and on the small units, fire teams, squads, and platoons, where combat is ultimately decided. By centering training on controlled, competitive experiences of fighting, it reinforced the reality that wars are not won in abstraction, but in decisive moments of physical dominance at close range.

Combatives builds practical fighting ability, but it also exposes soldiers to controlled experiences of aggression, competition, fear, and a kind of toughness that is distinct from the endurance required for long movements under load or difficult terrain. It is the toughness required to engage another human being directly, to impose one’s will in close contact while maintaining control and discipline. Through progressive training, soldiers learn how to manage those forces rather than being overwhelmed by them.

This systematic approach to fighting meshed naturally with the Ranger method of close combat, which emphasizes surprise, speed, and violence of action. Combatives provided a structured way to develop the individual and small-unit skills required for those decisive moments, while remaining flexible enough to adapt to any mission or objective. The goal was never simply to produce better fighters, but to build warriors capable of operating effectively and responsibly in the violent environments they might one day face.

Over time, however, another question began to emerge. As I continued teaching and studying combat, I became increasingly interested in the psychological consequences of violence. I came into the Army at a time when PTSD had already been recognized as a defining consequence of war, particularly in the aftermath of the Vietnam War. The dominant framework focused on trauma, on how the human nervous system responds to extreme stress and threat (American Psychiatric Association, 2013). That framework explained many things, but it did not explain everything. Over time, it became increasingly clear that some of the burdens carried by returning warriors were not rooted in fear or survival at all. They were rooted in something else entirely, something that had to do with meaning, responsibility, and the violation of deeply held beliefs. The term that has come into use for this phenomenon is moral injury (Litz et al., 2009; Shay, 1994).

When I began reading the existing literature on the subject, I was struck by something that did not quite fit with my own experiences in combat and training. The dominant framework, both in efforts to build resilience before combat and to treat veterans afterward, was built on the assumption that the primary injury of war is trauma. Much of the discussion of moral injury was layered onto that same model, treated as a clinical issue that emerges after war and must be addressed through therapy and counseling (Maguen & Litz, 2012). While those approaches can certainly help some individuals who are suffering, they did not seem to fully explain the underlying problem.

My experience suggested that something deeper was happening.

The dominant psychological model treats conditions like PTSD as injuries arising from exposure to extreme threat and stress, with war functioning as a primary context for that exposure. That framing makes sense if we view such conditions as deviations from a baseline of safety. But from an evolutionary perspective, that assumption does not hold. Human beings did not evolve in safety. Our nervous systems were shaped over millions of years in environments defined by threat, predation, and competition (Tooby & Cosmides, 1990; Nesse & Williams, 1994). Every organism that survived long enough to reproduce did so under conditions where death, often violent death, was a constant possibility. In that sense, war is not an aberration from the conditions that shaped us. It is a concentrated expression of them.

When viewed from that perspective, war does not create an entirely new reality. It reveals what the world, and people, really are.

The more I thought about it, the more it seemed that the roots of the problem often begin long before a warrior ever goes to war. They begin with the moral framework he carries with him into combat. If that framework is built on assumptions about human nature and violence that do not survive contact with reality, then the experience of war can shatter it. The injury is not caused by war itself, but by the collapse of a moral system that was never fully aligned with the truth.

Trying to understand that problem led me deeper into the study of psychology, anthropology, and evolutionary biology. I began asking a broader question: what kind of moral and psychological framework actually prepares human beings for the realities of conflict?

To answer that question, we have to begin much deeper than modern psychology. We have to begin with the conditions under which life itself evolved.

From the earliest forms of life, survival has depended on the ability to detect threats, avoid predators, and in many cases to kill and consume other organisms. The evolution of nervous systems, perception, and eventually brains was driven largely by predator-prey dynamics. Life evolved under conditions where violence was not an anomaly but a constant pressure shaping behavior and cognition (Dawkins, 1976; Pinker, 2011).

As social animals emerged, another layer of conflict appeared. Many species compete violently with members of their own species over territory, status, and mates. In a smaller number of species—including chimpanzees, wolves, and humans—coalitions of individuals cooperate to compete with rival coalitions. These coalitionary conflicts can escalate into organized violence resembling primitive warfare (Wrangham & Peterson, 1996; Boehm, 2012).

Human beings evolved inside this ecological and social landscape. Our psychological architecture reflects it. We are capable of empathy and cooperation, but we are also capable of aggression, rivalry, and organized violence in defense of our groups. For most of human history, communities survived because some of their members were willing and able to fight when necessary.

Across cultures and centuries, societies developed moral systems to regulate this reality. Warriors were expected to use violence when required to protect the group, but they were also bound by rules governing how that violence was used. Codes of honor evolved to channel aggression outward toward enemies while restraining it within the coalition itself.

These codes served a practical purpose. Coalitions that could fight effectively without descending into internal betrayal or uncontrolled brutality were more likely to survive. Honor traditions created expectations of courage, loyalty, restraint, and accountability that allowed groups of armed men to function together under extreme conditions.

In that sense, what we call a warrior ethos is not a cultural accident. It is a cultural solution to a very old evolutionary problem.

The difficulty is that modern societies have become increasingly disconnected from these realities.

Most of us grow up in what I call the protected world. Modern societies are highly specialized. The vast majority of citizens rarely encounter violence directly. Security is provided by a small number of soldiers, police officers, and other professionals operating on behalf of the larger society.

In this protected environment, moral systems tend to develop around assumptions of safety and order, assumptions that are adaptive within that environment but incomplete outside of it. Children are often taught that people are basically good, that violence is abnormal, and that moral decisions are simple and clear if one only follows the rules. These ideas can function well enough in peaceful settings, but they are fragile. They rest on conditions that depend on others confronting dangers on behalf of the group.

When someone raised inside that protected moral system encounters the reality of war, the results can be deeply destabilizing.

War reveals truths about human nature that polite society often avoids. Human beings are capable of cruelty, betrayal, and violence on a scale that is difficult to imagine from the safety of ordinary life. Combat places individuals in situations where decisions must be made quickly, under extreme stress, often with incomplete information and tragic consequences.

A young man raised to believe that violence is always wrong may suddenly find himself responsible for using lethal force to protect his comrades. He may face situations where every available option carries moral cost. He may discover that the enemy is capable of brutality beyond anything he imagined. He may also encounter failure, betrayal, or incompetence from leaders or institutions he trusted.

In those moments the moral framework he carries inside his own mind becomes critically important.

If that framework was built on comforting illusions about human nature and conflict, it may collapse when confronted with reality. When that happens, the individual is not simply experiencing trauma. He is experiencing the collapse of the moral architecture he used to understand himself and the world.

This is the root of what we call moral injury.

My approach begins from a simple premise: the moral foundation of a warrior must be built on truth. That means acknowledging the realities of human nature and conflict before war begins, not after. We must accept that human beings are capable of both good and evil. We must recognize that violence sometimes becomes necessary in the defense of others. And we must prepare warriors for the fact that war often presents situations that are tragic, ambiguous, and morally complex.

This does not mean abandoning morality. Quite the opposite. It means building a stronger and more realistic moral framework capable of surviving contact with reality.

Throughout human history, societies that depended on warriors developed codes of honor that served exactly this purpose. These codes channeled aggression where it was necessary while restraining it where it would destroy the group. They demanded courage in the face of danger, loyalty to comrades, restraint toward the helpless, and accountability for one’s actions. They defined what was honorable conduct in war and what crossed the line into shame or dishonor.

These traditions were not romantic decorations. They were functional systems developed by communities that depended on warriors for survival. A coalition of fighters cannot endure if its members turn their aggression against one another, abandon their comrades, or descend into uncontrolled brutality. Honor codes existed to preserve cohesion, trust, and discipline within groups that faced extreme danger.

In my work developing and teaching the Modern Army Combatives Program, I have tried to apply these principles in a modern context. Realistic training matters, not only because it prepares soldiers physically, but because it prepares them psychologically and morally. Progressive, reality-based training exposes fighters to the stress and dynamics of violence in controlled ways. It allows them to experience aggression, fear, competition, and responsibility within a framework governed by rules and accountability.

This kind of training does more than build skill. It helps create mental models that warriors can use to interpret their experiences in combat. When people have already confronted the reality of violence in training and have been guided by a clear code of conduct, they are less likely to experience confusion or collapse when they face those realities in war.

Another major part of the problem is cultural. Modern societies have become increasingly disconnected from the realities of danger and defense. Most citizens live their lives inside a system of safety maintained by others. As a result, the moral language that develops inside the protected world often diverges sharply from the experiences of those who operate in the exposed world of conflict.

This divergence can create a dangerous gap. Warriors may return from war to find that the society they defended does not understand what they experienced or why certain actions were necessary. In some cases they may even face moral condemnation from people who have never confronted similar realities. At other times the betrayal comes from within institutions themselves, when leaders fail to take responsibility for decisions made in war (Shay, 2002).

These experiences can deepen moral injury because they undermine trust and meaning. The warrior is left feeling that the values he thought he was serving have been abandoned or denied.

At the center of my approach are three principles that follow from these observations.

First, a warrior’s moral foundation must be grounded in truth about human nature. Human beings are capable of both cooperation and violence. Conflict between groups is a recurring feature of history, not an aberration. Preparing warriors requires acknowledging these realities rather than shielding them from them.

Second, societies must maintain functional systems of honor that regulate the use of violence. Honor codes are not archaic traditions or romantic ideals. They are practical systems that channel aggression outward toward legitimate enemies while enforcing discipline, loyalty, and restraint within the group. Without such systems, armed coalitions tend to fracture internally or descend into destructive brutality.

Third, preparation must occur before war, not only after it. Psychological and moral preparation should be as much a part of training as physical skill. Warriors who understand the realities they may face, and who possess a coherent moral framework for interpreting those realities, are better equipped to endure the pressures of combat without losing their sense of integrity.

Closing the gap between the protected world and the exposed world of conflict will not eliminate the tragedy inherent in war. But it can reduce confusion, betrayal, and moral collapse.

Ultimately my goal has been to help rebuild a warrior ethos grounded in truth. Such an ethos prepares men for the realities of conflict without glorifying violence. It channels aggression in defense of others while maintaining discipline and restraint. It provides warriors with a moral framework capable of surviving the pressures of combat. And it helps ensure that when they return from war they can remain not only effective fighters, but also healthy husbands, fathers, and citizens.

A society that asks men to fight on its behalf owes them at least this much: a moral foundation strong enough to survive the truth about the world.

References

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.).

Boehm, C. (2012). Moral origins: The evolution of virtue, altruism, and shame. Basic Books.

Dawkins, R. (1976). The selfish gene. Oxford University Press.

Litz, B. T., Stein, N., Delaney, E., Lebowitz, L., Nash, W., Silva, C., & Maguen, S. (2009). Moral injury and moral repair in war veterans. Clinical Psychology Review, 29(8), 695–706.

Maguen, S., & Litz, B. T. (2012). Moral injury in veterans of war. PTSD Research Quarterly, 23(1), 1–6.

Nesse, R. M., & Williams, G. C. (1994). Why we get sick: The new science of Darwinian medicine. Vintage.

Pinker, S. (2011). The better angels of our nature: Why violence has declined. Viking.

Shay, J. (1994). Achilles in Vietnam: Combat trauma and the undoing of character. Scribner.

Shay, J. (2002). Odysseus in America: Combat trauma and the trials of homecoming. Scribner.

Tooby, J., & Cosmides, L. (1990). The past explains the present: Emotional adaptations and the structure of ancestral environments. Ethology and Sociobiology, 11(4–5), 375–424.

Wrangham, R., & Peterson, D. (1996). Demonic males: Apes and the origins of human violence. Houghton Mifflin.