The Ethics of Military Ethics: Teaching Right and Wrong to People Trained to Kill

Editors' note: This essay is part of the 2026 Global Ethics Day online exclusive roundtable from Ethics & International Affairs. View the whole collection here.

The Ethics of Military Ethics: Teaching Right and Wrong to People Trained to Kill

What does it mean for an institution to “center ethics”? It begins, surely, with the recognition that ethics is a distinct practice and not, as it is too often thought of, a synonym for law and legal compliance. To center ethics one must also center people—a core function of ethics is to interpose itself between abusive power and the innocent. Lastly, to center ethics one must eventually move out of clean, abstracted theory into the messy, frequently ugly, and invariably unsatisfying practical—the moral world of dilemmas, trade-offs, and chronic uncertainty.

In this brief essay, I reflect upon my own efforts, in the United Kingdom, Germany, Denmark, and Australia, to teach ethics to militaries, from cadets to senior officers. I begin by reflecting on the status and value of military ethics education today, and then detail two concerns: first, the devaluing of the innocent in military thinking; and second, the increasing prioritization of speed and optimization in war and the potential negative effects of both for military ethics.

War is Hell?

When I tell people what I do for work—research and teach military ethics—the response I sometimes receive (with various degrees of smugness) is “that’s an oxymoron, isn’t it?” This is an old and stubborn idea: that war is a realm fundamentally incompatible with restraint, controls, and decency. It is hell, and ethics cannot operate in hell.

Today, one could be forgiven for entertaining this dismal view of armed conflict. War crimes are defended¹ and sometimes celebrated² by political elites and the media; the legitimacy of the International Criminal Court is under assault³; and dehumanizing and genocidal language is an increasingly common accessory to battlefield violence.⁴ So yes, I understand the impulse to dismiss military ethics training as a quixotic folly, or worse, an insidious distraction from our true moral task: doing away with war entirely.

Before we jettison military ethics, however, we should think carefully about the alternatives. To look at the warfare of today and conclude that it is as cruel, destructive, and purposeless as it can be is simply a failure of imagination. A brief glance at history is all the reminder one needs of what armed conflict can become when we abandon even the pretense that ethics matter.

War is an institution that ruins the lives of the innocent at scale. Military ethics was not developed to rescue war from this state, but rather, to reduce the unjust infliction of harm as much as feasible. This matters. Unsatisfying as it inevitably is, military ethics, and the actions it steers combatants from and toward, can help keep innocent people alive who would otherwise die, and allow those who fight to preserve something within themselves they would otherwise lose.

This is not to argue that military ethics training is in perfect shape; it is not. To retain its value, military ethics must better respond to the forces that challenge it.

Devaluing the Innocent

My first concern regards the status of the innocent in war. Great Power competition has returned, the consensus informs me, and militaries must modify their force design and doctrine accordingly. It is not just the United States, the United Kingdom, or Australia, but the West that is allegedly under assault from the new forces of barbarism.⁵ In discussions ranging from civilian immunity⁶ to the design and use of increasingly autonomous weapons,⁷ there is a growing call to embrace more permissive modes of war. I hear similar things in university and military classrooms across multiple nations—yes, our ethical rules have value, but in future war, fought for existential stakes against peer adversaries, they must be relaxed lest we render ourselves prey in a world of predators. This ruthless consequentialism gives little attention to the innocent who may find themselves on the wrong end of our shifting approach to violence.

It should be noted that some militaries, such as the Australian Defence Force (ADF), explicitly reject consequentialism as the principal guide for moral decision-making among the enlisted. The ADF cites its potential to justify “unethical acts.”⁸ Countering this shift to more ruthless means-ends thinking in practice, however, is a more difficult task, given the current dominant belief that future war will be fought increasingly along Great Power, or even civilizational, lines.⁹

To push back against such thinking in training, I and other military instructors will typically bring up virtue ethics, an alternative normative theory to consequentialism and deontology. Virtue ethics, centered on questions of good character rather than consequences or inherent moral worth, has long been seen as “functionally indispensable” to the profession of arms.¹⁰ Virtue ethics provides, it is argued, a “kind of moral and psychological armor that protects the warrior from becoming a monster in his or her own eyes.”¹¹

This is a compelling, and often useful, narrative. Do not compromise your integrity in the pursuit of your goals, we urge, or you may not be able to live with yourself in later years. Do not commit war crimes against the innocent or the defenseless or you may suffer moral injury, the psychological damage resulting from action (or inaction) that violates one’s own moral code.¹² Even within this ethical framing, ends (specifically, combatant ends) receive most of the focus—be good in order to claim the reward of a clean conscience and untroubled sleep. Missing, again, are the innocent, functioning merely as tests for the enlisted to pass or fail.

I understand the growing appeal of this sort of thinking. When the geopolitical stakes are high enough, states and students alike prioritize strategic outcomes and survival over the categorical rules and principles of deontology. States do confront complex and evolving security challenges. Militaries are facing hard questions regarding the emerging technologies they acquire, the regulatory frameworks they adopt, and the battlefield standards they authorize. But these decisions are infused with ethical weight. Military ethics is at its best not when it denies the force of exigency, but when it refuses to let that be the final word.

It is also true that questions of virtue do and should play a vital role in military ethics. The preservation of your soul is a very good reason not to engage in criminal and murderous acts. But we must never pretend that it is the only reason. Too often in military ethics, the perspectives, experiences, and miseries of the belligerent are prioritized to the near-total exclusion of civilian voices.¹³ This lack of emphasis leaves military ethics vulnerable to licensing, rather than inhibiting, bad conduct. In some cases, war crimes will bring you closer to victory, and those who commit such actions will not always be haunted by the weight of their sins. It is critically important for those who teach military ethics to remind those who fight that the rules of war matter, ultimately, because the innocent matter. They have a moral status and value that cannot be overridden, regardless of the outcomes you guess at or the aspects of character you compromise.

The Ethics of Systems

My second concern relates to the role of ethics in the future of warfare that militaries are working to bring about. Much of our focus as educators within military ethics is on the problematic conduct of soldiers, units, and commanders—indiscriminate or disproportionate killing, atrocities, enemy abuse, and so on. We work to instill a knowledge of the rules, a respect for their importance, and an understanding of the baleful consequences of their violation. We talk through scenarios where combatants are tempted or instructed to break the rules and offer guidance for resisting both.

There are a number of assumptions embedded in this approach. We assume a willingness on the part of the combatant to self-reflect—to think meaningfully about the likely effects of misconduct on the mission, the victim, and themselves. We also assume a capacity to self-reflect. Passing a test of integrity or successfully navigating a complex moral dilemma often requires a slowing down. A careful consideration of the political, legal, and moral dimensions of the issue. A consultation with hard-earned experience and wisdom. A consideration of trade-offs. It requires, in other words, inefficiency.

My concern is that inefficiency is an increasingly dirty word within militaries. Underpinning much of the optimism over, and allure of, emerging technologies, including military AI, is an exaggerated faith in acceleration and optimization. Through both, future war planners hope to streamline and compress decision-making processes, eliminate inefficiencies, and radically increase both the speed and scale of violence—systems of systems, fully networked and operating, by design, at speeds that humans cannot replicate.

Where does this leave the self-reflecting combatant? Nowhere good I suspect. The talk is increasingly of augmented and empowered humans. Humans leveraging technology to absorb and analyze data more efficiently. Humans drawing on AI systems to make better decisions faster. But ethics does not always work this way. It resists being packaged into an algorithmic checklist. It is my belief that violence at certain speeds simply forecloses the capacity (and often inclination) of combatants to meaningfully consider their ethical responsibilities. What we are left with instead are morally inert actioning devices.

What does this mean for military ethics? First, those of us who teach it should broaden our own moral horizons and consider not just the ethics of individuals and actions, but also those of systems. Which military systems best preserve the moral agency of the humans that constitute them, and which enfeeble and deaden the human as a moral force? We must also recognize that for a growing number of military roles, the relationship between problematic action and problematic effects will be more tenuous. The scenarios we use in the classroom should reflect this and focus on the unjust harms that combatants may contribute to unintentionally and indirectly, but foreseeably.

In my own teaching on technology and war, the students and I increasingly discuss the potential of technology to shape patterns of vulnerability between people, exacerbate uncertainty, and weaken our ability to assign accountability for wrongful harm. The character of war is being actively reshaped by the integration of AI, the systematization of conflict, and the relentless push toward more accelerated violence. I encourage my students to think meaningfully about how much risk civilians and other innocent parties should bear for these choices.

Lastly, we should forcefully push back against the claim that ethics can easily and always be maintained within heavily optimized systems. Inefficiency, slack, friction, lag— whatever you want to call it—some degree of space and time is critical for certain modes of ethical deliberation, and if these modes matter to us, we should talk seriously about what we are willing to give up to preserve them.

The Future of Military Ethics

War and the violence it entails is an increasingly technological endeavor. States and their militaries harness a range of tools—artificial intelligence, sensors, algorithms, robotics, machine learning, large-language learning models—to kill faster and more efficiently. Ethics, on the other hand, is about people. Human dignity, human wellbeing, human flourishing, and human suffering. Strip away the affected human and ethical questions lose all substance. Those who teach military ethics ought not to forget this.

—Neil Renic

Neil Renic is a lecturer in ethics at the University of New South Wales, Director of the Military Ethics Research Lab and Innovation Network (MERLIN) and member of the International Committee for Robot Arms Control (ICRAC). Renic specializes in the changing character of war, the ethics of killing, and emerging military technologies.

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