Soldiers as Public Officials: A Moral Justification for Combatant Immunity

• DOI: http://doi.org/10.1111/raju.12256
• Author: Malcolm Thorburn
• Date: 01 December 2019
• Published date: 01 December 2019

© 2019 The Author. Ratio Juris © 2019 John Wiley & Sons Ltd.

Ratio Juris. Vol. 32 No. 4 December 2019 (395–414)

Soldiers as Public Officials: A Moral

Justification for Combatant Immunity

MALCOLM THORBURN*

Abstract. How can we make moral sense of the international humanitarian law doctrine of com-

batant immunity? The doctrine is morally shocking to many: It holds soldiers on both sides of

a war immune from criminal prosecution for their otherwise criminal acts of killing, maiming,

destroying property, etc., carried out as part of their country’s war effort. That is, soldiers who

kill as part of an attack benefit from the immunity just as much as those defending their coun-

try. Traditionally, just war theorists have tried to provide situation-specific arguments to show

that soldiers on both sides had a good moral justification for their actions. Recently, self-styled

“revisionist just war theorists” have suggested that the doctrine of combatant immunity is just

a convention designed to minimize harm. In this article, I suggest that the moral foundation of

the doctrine lies in the status of soldiers as public officials in the service of their country. The

reason why we hold them immune from prosecution for their war-making acts is that such acts

are properly thought of as acts of a state, rather than as acts of a particular individual. And the

reason why states are immune from prosecution for their acts is one of moral standing: No other

state has the moral standing to tell another how to carry out the matters that define its juris-

diction. So as long as a country deems (however implausibly) that it must use force to defend

itself from aggression, then it may do what is required to defend itself. No other state has the

standing to prohibit such acts or to punish those who carry them out. This argument is rooted

in an understanding of how individuals may interact as free and equal under law. It does not

aim at the perfection of human action, but it does serve to eliminate the worst forms of tyranny.

1. Introduction

In order to carry out their military objectives, soldiers routinely engage in actions that

would constitute the most serious crimes if committed in peacetime: They kill, they

wound, they destroy property, and much else besides. But under modern interna-

tional humanitarian law (IHL) as set out in the Third Geneva Convention, they are

immune from criminal prosecution for those acts so long as they abide by IHL

norms requiring discrimination between combatants and noncombatants and

* This paper is the descendant of one first presented at the Oxford Centre for the Ethics and Law

of Armed Conflict (ELAC) held in Stockholm, Sweden, in the summer of 2015, organized by

Jonathan Parry and Helen Frowe. The present version of the paper was presented at a workshop

at Pluricourts in Oslo, Norway, organized by Alain Zysset and Ryan Liss in the summer of 2017.

I would like to thank the organizers and audiences at both events for excellent comments and

questions. Responsibility for all remaining errors remains with me, the author.

Malcolm Thorburn

396

Ratio Juris, Vol. 32, No. 4© 2019 The Author. Ratio Juris © 2019 John Wiley & Sons Ltd.

proportionality between harm and military advantage.1 What is more, this immunity

from criminal prosecution and punishment applies equally to combatants on both

sides of a war: That is, it applies not only to soldiers defending their country, but also

to the soldiers on the other side, carrying out their country’s aggression. So, for in-

stance, although Nazi Germany was indisputably an unjustified aggressor in its in-

vasion of Poland in September of 1939, the soldiers in the German Wehrmacht would

be treated as “privileged combatants” under IHL (and therefore immune from crim-

inal prosecution) in just the same way as the Polish soldiers who were defending

their country from German invasion.

All this is settled law. In this essay, I focus on two further questions: Can this legal

state of affairs be morally justified and, if so, how? These questions have greatly trou-

bled moral philosophers over the centuries and particularly in the past few decades.2

Two broad schools of thought dominate the current debate. The first camp is what is

often called “orthodox just war theory,” the best-known advocate of which is Michael

Walzer. On this account, the immunity of lawful combatants from criminal prosecu-

tion for their otherwise criminal conduct is morally justified because their conduct

itself is morally justified under the circumstances. The second account is what is

often called “revisionist just war theory,” the best-known advocate of which is Jeff

McMahan. Revisionists reject the orthodox strategy of justifying combatant immu-

nity on the grounds that their conduct itself is morally justified. Nevertheless, they

insist, the rule holding combatants immune from prosecution is morally justified on

the grounds that it tends to prevent more harm than it causes.3 As McMahan (2009,

107) puts the point, “the law of war is designed not to protect rights but to prevent

harm.”

In this essay, I argue that both the orthodox and revisionist moral justifications of

combatant immunity are wrong. The failures of the orthodox account are fairly obvi-

ous when we consider some egregious examples of unjustified state aggression.

Whatever else we might say about the situation of Wehrmacht soldiers invading

Poland in 1939, it is just not plausible to suggest that they were morally justified in

acting as they did. The failures of the revisionist balance-of-harms account are less

obvious, but no less important. For whatever the merits of the empirical claim that

combatant immunity prevents more harm than it causes, this sort of argument cannot

provide a justification for a rule of this importance. We can see this clearly in the

1 The Geneva Convention relative to the Treatment of Prisoners of War (the Third Geneva

Convention) was adopted in 1949, replacing the Geneva Convention of 1929; it governs the

treatment of prisoners of war. Under the Convention, enemy combatants may only be captured

as prisoners of war, to be released upon the end of hostilities. They may not be punished for any

killing (so long as it took place according to the norms of IHL requiring discrimination between

combatants and noncombatants and proportionality between harm and military advantage).

2 The contemporary debate has a different flavour than the just war debates of centuries past

because of two important developments. The first of these is the legal prohibition on aggressive

war set out in the Kellogg-Briand Pact (1928) and now in the UN Charter (1945). The second is

the legal equality of combatants set out in the Third Geneva Convention (1949).

3 This instrumentalist argument may be drawn in terms of harm-reduction (as McMahan does)

or it may simply be a description of the interaction of “prosaic” matters of state self-interest to-

gether with the design of incentives. In this regard, see Haque (2017, 28): “No state wants its

own soldiers prosecuted by its adversaries, and so all states agree not to prosecute the soldiers

of their adversaries. In addition, such a legal immunity gives soldiers determined to fight an

incentive to fight within the constraints of international law.”