Reciprocity Without Retaliation: Rethinking Fairness in the Laws of War

Editors’ note: This post is the second in a series relating to the author’s book, The Persistence of Reciprocity in International Humanitarian Law, published by Cambridge University Press. The first post in the series is available here.

In the first post of this series I argued that reciprocity continues to shape international humanitarian law (IHL) even though the Geneva Conventions formally reject conditional restraint. IHL promises protections “in all circumstances” in Common Article 1 because humanity demands it, not because adversaries behave well. Nevertheless, expectations of reciprocal restraint remain central to how States, combatants, and societies think about fairness in practice.

This tension often produces the mistaken belief that reciprocity is inherently illiberal and that to acknowledge it is to justify retaliation or to erode the moral foundations of IHL’s obligations. But reciprocity need not mean vengeance. It need not imply that humanitarian protections are a bargain or a threat.

Instead, reciprocity can signify recognition; the basic acknowledgement that an adversary is a moral and legal subject capable of restraint and that mutual commitment sustains the legitimacy of law. This post explores this idea. It maps different forms of reciprocity in war, shows how they operate alongside legal norms, and argues that reciprocal recognition is a foundation of humanitarian restraint rather than a threat to it.

Forms of Reciprocity in War

To align the terminology with my book, it is useful to clarify how specific legal reciprocity and specific strategic reciprocity operate in today’s asymmetric conflicts, where symmetry of status, power, or obligation often collapses.

Specific legal reciprocity refers to the formal, codified conditionality found in earlier laws of war. It rested on symmetry: equivalent obligations; similar status; and mutual capacity to reciprocate. Its logic was abolished by the Geneva Conventions, which demand adherence “in all circumstances.”

Specific strategic reciprocity, by contrast, is motivational rather than legal. States restrain themselves because doing so supports legitimacy, reputation, operational advantage, or future reciprocal claims. It can occur with either equal or unequal opponents.

This taxonomy shows that reciprocity does not disappear when formal legal symmetry collapses; instead, specific, diffuse, and strategic forms of reciprocity adapt to shape behavior even in highly unequal conflicts.

Reciprocity is usually imagined as tit-for-tat behavior: restraint traded for restraint and violation punished with reprisal. That narrow understanding is common in older military manuals and realist accounts of war. But reciprocity is not one thing. It has multiple forms, some transactional, others deeply ethical.

In my book, I distinguish three core types of reciprocity: specific reciprocity; diffuse reciprocity; and strategic reciprocity. In contemporary conflicts, these forms increasingly operate in deeply unequal or asymmetric settings.

Specific Reciprocity

Specific reciprocity is the simplest and most intuitive form. It is immediate and symmetrical: “We hold fire because you did.” In war, this logic historically governed prisoner exchanges, truces to collect the wounded, and battlefield conduct among professional armies. We see echoes of this even today. Russia and Ukraine have engaged in regular prisoner exchanges. Parties in Yemen have negotiated temporary truces to facilitate humanitarian access. These gestures reflect a basic reciprocal instinct: if restraint is offered, one should respond in kind.

IHL tries to limit this logic. The Geneva Conventions prohibit reprisals against protected persons precisely to prevent humanitarianism from devolving into conditionality. But specific reciprocity still operates in practice; not as a formal legal principle but as a behavior that helps compliance take root.

Diffuse Reciprocity

Diffuse reciprocity is broader and more social. It is grounded in long-term expectations, not immediate exchange. States comply with humanitarian law not because they expect an instant return from an enemy but because compliance builds a reputation, reinforces legitimacy, and reciprocates a shared commitment to norms.

This is the logic of institutional trust. It underpins participation in the Geneva system, respect for the International Committee of the Red Cross (ICRC), and State practice around the treatment of detainees.

When commanders tell troops to treat prisoners humanely because “that’s what makes us different,” they invoke diffuse reciprocity. They are appealing to identity, reputation, and a shared legal culture, not transactional exchange. This form of reciprocity sustains humanitarianism precisely when specific reciprocity may fail, such as in conflicts with armed non-State actors or those that routinely violate IHL.

Strategic Reciprocity

Strategic reciprocity operates in the space between morality and pragmatism. It recognizes that restraint can be instrumentally valuable by preserving legitimacy, building alliances, encouraging cooperation from civilian populations, and reinforcing claims about future mistreatment.

It is strategic, not in a cynical sense, but in the sense that ethical conduct and self-interest are aligned.

Debates within the United States after 9/11 illustrate this well. Some argued for departing from the Geneva protections on the grounds that terrorist groups did not reciprocate. Others such as former prisoner of war (POW) John McCain insisted that adhering to IHL even when adversaries did not was essential to maintaining reciprocal claims and moral legitimacy. The Supreme Court’s decision in Hamdan v. Rumsfeld (2006) affirmed that Common Article 3 applied even in conflicts with non-State actors and embedded reciprocal restraint in legal doctrine.

Both positions assumed reciprocity mattered but the debate concerned its form: punitive symmetry or principled restraint. Strategic reciprocity helps explain why many democracies ultimately concluded that compliance with IHL would strengthen rather than weaken their security.

Reciprocity in Asymmetric Conflicts

Modern warfare is rarely fought between equals. States confront insurgent groups, terrorist networks, cyber actors, and proxies. In such contexts, equal obligation is impossible. Yet mutual recognition and reciprocal expectations may still arise. Humanitarian corridors negotiated with non-State groups, prisoner releases involving armed groups, and public messaging emphasizing humane treatment are all examples of reciprocity operating under conditions of deep inequality.

These practices draw on elements of specific legal reciprocity (as a background legal expectation), diffuse reciprocity (as shared normative commitment), and strategic reciprocity (as a calculation about legitimacy, reputation, and future treatment), even when only one side is formally bound by the law.

Understanding this form of reciprocity is critical in today’s conflicts. It reveals how humanitarian norms survive when symmetry collapses.

Reciprocity as Ethical Recognition

If specific reciprocity imagines the enemy as a counterpart and diffuse reciprocity imagines a community of observers, then reciprocal recognition imagines something deeper: the enemy as a moral subject.

Philosophers have long argued that ethical obligations require seeing the other as capable of moral agency. To act humanely toward a combatant is to acknowledge their humanity even when they threaten yours. In IHL, that recognition is institutionalized. To grant POW status, to permit ICRC access, to treat an enemy hors de combat with care is to reciprocate an assumption of shared humanity. In this sense reciprocity is not a bargain. It is a structure of moral acknowledgement. It is what makes humanitarian law more than a collection of rules, what gives it ethical meaning.

Critics may worry that recognizing reciprocity risks conditionality. If the enemy is not humane, why should we be? But the answer is not to deny reciprocity, it is to elevate it. Reciprocal recognition need not collapse when reciprocity of conduct fails.

Indeed, the prohibition on reprisals against protected persons transforms reciprocity. It channels reciprocal instincts away from retaliation and towards principle. Law reworks reciprocity rather than abolishing it.

The Moral Economy of Restraint

Law does not enforce itself. It depends on shared beliefs, reputational incentives, and mutual expectations to create a moral economy of restraint.

Reciprocity animates this moral economy. It encourages actors to see restraint as socially meaningful and not merely as self-denial. When States comply with IHL they expect acknowledgement from allies, publics, and international organizations.

That expectation is reciprocal. It rests on the belief that humanitarian behavior will be recognized and rewarded over time. This is not idealism. It is how law works in practice. Norms survive not only through coercion but through reciprocal belief in their value. Without that shared belief, legal obligation thins into abstraction.

From Retaliation to Recognition

One of the great achievements of IHL is not that it abolished reciprocity but that it civilized it.

Early codes accepted reciprocal retaliation as natural. The Lieber Code permitted reprisals under certain conditions. The Geneva Conventions, particularly after 1949, transformed this logic. They prohibited reprisals against POWs and civilians replacing reciprocal vengeance with reciprocal recognition.

Restraint today is not conditioned on enemy conduct. It is justified by belonging to a community of States that recognize one another as subjects of law. It is a diffuse and strategic reciprocity rooted in dignity.

That shift was not the rejection of reciprocity. Rather, it was its elevation. It moved reciprocity from symmetry to principle, from retaliation to restraint.

Conclusion

Reciprocity persists in humanitarian law because it expresses a basic intuition: justice in war requires mutual recognition. The challenge is not to eliminate reciprocity but to distinguish its ethical forms from its destructive ones.

Specific reciprocity can maintain compliance when restraint is returned in kind. Diffuse and strategic reciprocity sustain humanitarian norms when symmetry breaks down, revealing how mutual acknowledgment can survive even in contemporary conflicts defined by unequal power and uneven obligation.

This is not a story of law versus reciprocity. It is a story of law reshaping reciprocity into a vehicle for dignity in war.

In the final post in this series, I turn to the future. Can reciprocal restraint survive new forms of conflict, from drone warfare to great power competition, from hybrid threats to non-State violence where symmetry, recognition, and even shared reality are strained? If reciprocity is a fragile moral economy that sustains humanitarian norms, then the question for the 21st century is simple: can we preserve reciprocal recognition in wars where mutuality is collapsing?

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Bryan Peeler is the Assistant Professor and Associate Head of the Department of Political Science at University of Manitoba.

The views expressed are those of the author, and do not necessarily reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense. 

Articles of War is a forum for professionals to share opinions and cultivate ideas. Articles of War does not screen articles to fit a particular editorial agenda, nor endorse or advocate material that is published. Authorship does not indicate affiliation with Articles of War, the Lieber Institute, or the United States Military Academy West Point.

 

 

 

 

 

 

 

Photo credit: Army 1st Lt. Jonathan Sauls