May the Well-Being of Non-Combatants

Be Directly Attacked as a Tool of War?



presented to the

Joint Services Conference on Professional Ethics

Washington, DC

30 January 2004



Robert G Kennedy, PhD

Professor of Management and Catholic Studies

University of St Thomas

Mail #55-S

St Paul, MN 55105

VOX: 651 962 5140                       FAX: 651 962 5710





The Principle of Non-Combatant Immunity (NCI), or Discrimination, is well established in contemporary discussions of just war theory and in international law. In its most general form it prohibits direct, intentional attacks upon non-combatants.[1] Nevertheless, despite its broad acceptance, a number of questions about its meaning and application remain unresolved. The purpose of this paper is to address some of these questions and to propose resolutions for further discussion.


Who are non-combatants?


One of the characteristics of modern Western civilization is a change in the conception of warfare. The American Civil War is sometimes called the first modern war, and perhaps it may be just that if one focuses on the introduction and use of new technologies (e.g., railroads, telegraph, repeating weapons, and so on). On the other hand, the Napoleonic Wars introduced in practice a conception that has played an important, and deeply mischievous, role in the major wars of the 20th century. This is the idea that war is rightly a conflict between whole peoples, in which virtually everyone has a role to play in carrying the war forward.[2]

To be sure, there are any number of examples in history of whole communities (cities, for instance, or tribes) that drew nearly every member into the activities of war, but these involved relatively small numbers of people or were occasioned by emergencies (such as a siege). Though it would rarely have been expressed this way, one of the characteristics that distinguished civilized peoples from barbarian tribes for much of Western history was the fact that war for the civilized peoples was the business of only a designated portion of the community.

In the Greece of the time of Socrates, it was the privilege and duty of citizens to be combatants as the need arose, and even then restricted to males of a proper age. In the normal course of affairs, the population, apart from these male citizens, did not fight. A similar observation could be made of the Romans and it was certainly also true of the civilized European communities of the Middle Ages.[3] In part, the segregation of the community into fighters and non-fighters might have been a natural result of the increasing technical demands of the Western methods of warfare, but it was also a consequence of the conviction that war was not the occupation of the whole community. That is to say, the whole nation did not go to war, the prince went to war, and many soldiers (and sailors) accompanied him out of loyalty or duty. The community might from time to time be at war, but this did not require the entire community to be directly engaged in the activities of war.

To be sure, non-fighters often suffered the consequences of war, especially when war entailed the siege of cities. The distinction of fighters from non-fighters often failed to convey to the non-fighters any significant protection from assault, injury, or even death. Gradually during the Middle Ages efforts were made to extend protections to non-combatants through prohibitions enacted by the Church and enforced by ecclesiastical penalties. These protections were first extended to clerics and later, in principle at least, came to include those who had not actually taken up arms in the conflict. Beginning in the 19th century the status of non-combatants and the protections to be afforded them found expression in international law.

It is ironic that at a time when the status of non-combatants was being defined by treaties, the concept of total war, of war as a conflict of peoples not armies, was also gaining currency. This is a legacy of the Napoleonic era and of Napoleon’s mobilization of the French nation for his imperial purposes, but its fullest expression would be found in the 20th century, especially in the Second World War and its aftermath. There, beginning with the German policy of unrestricted submarine warfare in the First World War and continuing through Allied policy of strategic bombing to the four-decade long standoff of nuclear deterrence, the distinction between combatant and non-combatant was virtually erased. The modern era, it was argued, was a time of “total war,” in which every member of the community was a legitimate target since every member could somehow be considered a combatant.

Such a claim, however, is and has always been untenable. The Just War tradition is rooted in the claim that the use of military force must be legitimized by, among other factors, a just cause. Such potentially deadly force can only be used in the service of peace and, by extension, only directly against those who act against (or who are prepared to act against) peace in a proportionately serious way.[4] A just war necessarily requires a just use of force, which in turn excludes direct assaults on innocent persons.

In practice the distinction between the innocent and the guilty in the context of war is difficult, perhaps even impossible, to make. In combat, where such distinctions become actually meaningful, it is impossible to gauge the innocence or guilt of another party. Is this enemy soldier or sailor an unwilling conscript, forced to serve in a war to which he does not consent? Is the unarmed civilian an ardent supporter of the conflict even though he does not fight? Who is innocent here and who guilty?

In the late Middle Ages and the early modern period the conviction grew incrementally that some members of communities in conflict ought to be spared the violence of war. The customary law of arms entailed a rationale for protecting civilians from harm in a siege, provided they removed themselves from the beleaguered city.[5] If not strictly a matter of justice, at least as a matter of military honor, civilians who heeded an authoritative command to surrender were not to be harmed.

Innocence as a criterion for determining membership in a protected class, however attractive it was for academic moralists, proved to be an unworkable criterion for those who actually had to make decisions about who should and should not be targeted. Similarly, the distinction between civilian and soldier, while clear in the abstract, is too easily blurred in practice, as the recent experiences in Israel and Iraq illustrate once again. Both must be discarded as practical foundations for assigning immunity.

A more promising criterion (though admittedly none will be perfect in application) is the distinction between those who directly participate in the activities of war (uniformed members of the armed services being the most obvious examples) and those whose activities are essentially peacetime activities. As combatants we may therefore include workers in munitions factories, programmers of weapons systems, and similar combat support functions, as well as the political leaders of the society.[6] But we must exclude from direct, intentional attack as non-combatants all those whose working activities support the general functioning of the society, such as farmers, fire-fighters (even though they may be called upon to extinguish fires caused by artillery and bombs), makers of military uniforms, and so forth. Surely to be classed as non-combatants are children, the disabled, and the elderly, among many others.[7] That members of each of these groups might vigorously agree with the war is irrelevant to the immunity they rightly possess.


Just War Theory and Non-Combatant Immunity


At first glance this would seem to be an unnecessary question, since it was acknowledged at the beginning of the paper that the Principle of NCI was broadly accepted. But is this really true? Early Just War theorists did not include NCI as one of their qualifying principles and indeed seemed to accept some direct, harmful consequences to non-combatants as a just outcome of war. The strenuous defense of NCI, and not merely defense of a prohibition of direct harm to certain classes (e.g., clergy), seems to be relatively modern.

Well, suppose that Just War theory has developed like so many other intellectual traditions and that we are now in clear agreement on a principle that was obscure to our predecessors. Even so, we can still ask whether we mean to defend a narrow or a comprehensive understanding of the principle.

The narrow understanding of the principle would merely assert that non-combatants are to be immune from all intentional uses of force that would, or could, cause death or gross bodily harm. It would be immoral on this understanding to engage in actions that, directly or indirectly, were intended to kill or seriously harm non-combatants. We might include within the definition of serious harm permanent injuries, rape, severe psychological trauma, and so forth.

At the other end of a continuum would be a comprehensive understanding of NCI, which in its widest scope could include all personal injuries, even those minor and temporary, all discomforts and inconveniences, as well as all damage to personal property.[8]

Before we come to a conclusion about where on this continuum we wish to locate a reasonable understanding of the Principle of NCI, let us consider what might be at stake.[9] That is to say, why and where would a military command (or its political superiors) be tempted to employ less-than-lethal force against non-combatants deliberately?


Less-than-Lethal Attacks on Non-Combatants


Consider three objectives for the use of less-than-lethal force (and others may be proposed as well).

First, someone might wish to attack non-combatants in order to undermine their resolve, or the resolve of the combatants, to continue the conflict. A strategy like this (though with deadly force) was famously pursued in the Second World War, and to some degree in Vietnam, without great success but perhaps this outcome had something to do with the nature of the totalitarian societies against which it was employed. Perhaps an argument could be made that it would be successful if used against a different society, or perhaps the less-than-lethal force itself would bring about a different result from strategic bombing.

Second, someone might attack non-combatants in order to draw needed resources away from military operations. If there were a way of denying food or fuel or some other commodity to a civilian population and that commodity could be supplied by drawing on military supplies, the effectiveness of the military could be reduced. Notwithstanding the general tendency of populations at war to endure sacrifices in order to keep the armed services supplied, this strategy might be effective in circumstances where the civilian population was not fully enthusiastic about the war in the first place, or where a high civilian standard of living would be severely and abruptly degraded.

Third, some military theorists argue that it is necessary that civilian populations realize that they have been defeated if peace is to be realized after combat has ceased. This may have been very much in the mind of General William T Sherman as he marched through the South in 1864. That is, since the Southern population had escaped the worst direct ravages of war, they were willing to continue the fight. Once Sherman brought the war to their homes, and not merely to distant battlefields, their attitude changed and they were willing to accept a negotiated peace. A similar argument might be made about the present situation in Iraq, though I think wrongly.

To round out this line of thought, we should also give some consideration to the means that might be adopted to pursue these ends. Given modern technologies and creative imaginations, we could easily develop a variety of less-than-lethal and even non-violent means of attacking non-combatants. But just what would we attack?

Well, we could attack the health of non-combatants in relatively minor ways. For example, we might find ways to deprive a civilian population of sleep or expose them to particularly aggravating sounds.[10] The damage done might be quite annoying even though it would be temporary. Interference with some food supplies could bring similar results.

We could also attack the economic well-being of the civilian population. War, of course, ordinarily causes this in any event, but steps could be taken to disrupt a banking system or to degrade a currency.[11] Private property could be damaged, especially wealth-producing property, which would have the further effect of putting people out of work and depriving them of an income.[12]

Information, communication, energy, and transportation systems could be disrupted, perhaps with minimal permanent damage.[13] This could be done not to deny the enemy armed forces the use of dual-purpose elements of the infrastructure but deliberately to hamper civilian populations in their ordinary activities.

Finally (though this is not meant to be an exhaustive list), we could assault the physical comfort and sense of security of a civilian population. Unpredictable energy disruptions could contribute to this as could the intermittent denial of other basic services. Furthermore, we could pursue a campaign of disinformation calculated to confuse and demoralize a population.

Each of these means would be less-than-lethal, at least in intention, and many would be simply non-violent. Yet each would constitute an attack on non-combatants if undertaken deliberately. On what grounds can we distinguish legitimate from illegitimate violations of NCI, or would all such attacks be unjustified violations of NCI?


How Far Does NCI Extend?


The answer we give to this question depends upon the foundation we identify for NCI in the most obvious case, which is immunity from lethal attack. But why should non-combatants be immune from direct, intentional lethal attack? Or perhaps we should ask why anyone would be justly susceptible to lethal attack.

The answer in the Just War tradition is expressed differently by different witnesses to the tradition but a reasonable summary explanation would be that those responsible for the well-being of a whole community (that is, the common good of that civil community) may use whatever force is necessary to protect the community—up to and including deadly force. This principle, applied internally to the community, justifies the use of deadly force to protect the community from criminals and even to administer capital punishment. Applied externally, the principle justifies the use of deadly force, of war, to defend the community from foreign armies (and navies) who would attack it unjustly.[14]

Of course, an underlying assumption is that the use of deadly force is only justified when lesser measures are reasonably judged not likely to be effective. Since the death of a human being is always an evil (though not always a moral evil), it must be avoided where possible.

The authority to use deadly force, however, is a specific case of a larger principle, which concerns the use of force to compel behavior. To be fully respectful of human dignity and freedom, changes in another person’s behavior should be brought about by persuasion, not force. However, when some persons, or groups of persons, seek to harm the common good and will not respond to persuasion, the civil authority may rightly employ whatever level of force is necessarily to compel them to change, or to prevent them from doing harm.

Two factors are key: the persons subject to the use of force must be engaged in doing significant harm and they must be resistant to persuasive efforts.

Do non-combatants fall into this category? By the definition we adopted at the beginning of this paper they do not. Even though they may endorse the war-making activities of their government and be correspondingly resistant to persuasion, they are not engaged directly in significant attacks on the common good that would warrant the use of force against them. Certainly they are not justly susceptible to the direct and intentional use of deadly force.

But what of lesser forms of force? The moral foundation that justifies the use of deadly force is the same foundation that justifies the use of force of any sort. To be justly subject to the use of force someone must be engaged in harm-doing but if non-combatants are engaged in harm-doing then, by definition, they are no longer non-combatants.

Furthermore, non-combatants are defined negatively, as those who do not belong to another particular class. Defined in this way, the class of non-combatants includes not only potential combatants but also those who cannot now and may never be combatants. As such, any direct attack on members of the class who, for example, might be engaged in encouraging a continuation of war, must entail an attack on natural non-combatants—which cannot be morally justified.

As a consequence, regardless of the level of force employed or the kind of harm intended, no direct, intentional attack on the person, property, or well-being of non-combatants can be justified.


What Are the Practical Implications of Comprehensive NCI?


Strategies that involve direct attacks on non-combatants are normally defended on a utilitarian basis. Such is the defense of Sherman’s march through Georgia and Truman’s decision to use atomic weapons against Japan. In both cases the argument is made be defenders that these actions brought the war to a swifter conclusion, thereby sparing many other lives, perhaps many more than were lost by these attacks on non-combatants. Such arguments, though, conclude confidently from premises that cannot be falsified or affirmed. We cannot know whether the Civil War would have been brought to a conclusion without Sherman’s action or whether the bitterness following the war might not have been lessened if Sherman had not marched. Nor can we know whether, in the months before an invasion of Japan could have been mounted, the Japanese government would have sued for peace. Such assumptions as under-gird these arguments simply do not support the conclusions.

What we do know, however, is that each of these actions—and many others could be adduced in the history of warfare—was a direct, intentional attack on a specific group of people that was know to contain a large number of non-combatants. In the case of the bombing of Japan, and Germany for that matter, the attack on non-combatants was clearly intended as a tool of war. This cannot be justified.

But what of other strategies, such as sieges, blockades and sanctions? Each of these practices is morally neutral in principle, which is to say that each could be employed legitimately against an enemy, but each would also be unjust if employed deliberately against a non-combatant population.

Setting aside a siege as an anachronism, we can consider blockades and sanctions. These both belong to the category of operations intended to deny the enemy important resources. If they are employed against groups containing non-combatant populations, they are morally licit to the degree that they focus directly on resources of military value and permit resources of importance to the non-combatants to reach them. Hardships caused to non-combatants can only be permitted, not intended.

Similarly, other tactics and strategies that have an impact on the well-being of non-combatants can be defended to the extent that they do not directly target this well-being. None of the practices described in the earlier section of the paper would pass this test and therefore none would be just.


One important temptation in modern warfare is to regard war as a conflict between peoples, partly because the tools of modern war can so easily reach everyone in the population. This, in turn, can lead us to think about every member of our own community and of the enemy community as a combatant of some sort. But clearly this cannot be so. No “total war” can be a just war. Just war theorists must defend the Principle of NCI, which entails immunity not only from deadly harm but from all sorts of harm to the well-being of non-combatants.



[1] This general statement of the Principle of NCI is well known. We need not go into a detailed discussion of its components except perhaps to say the following: An attack may be direct or indirect. A direct attack is one that is designed to have an immediate effect upon the subject of the attack, while an indirect attack produces an effect upon the subject through one or more intermediate causes. These descriptors tell us something about the means employed for the attack. The moral quality of the act, however, is determined by the intention of the attacker, which intention can concern both the means and the end, or object, of the attack (i.e., the state of affairs that the attacker wishes to bring about through his action). According to the principle of NCI, direct attacks are always prohibited (because, being direct, they are always intended) but indirect attacks may sometimes be licit (because, being indirect, they may be unintended consequences of direct attacks).

[2] The earliest discussions of just wars, as for example in Augustine, regarded war as a public act, which is to say an act of the community or society. Only the sovereign is authorized to initiate and prosecute a war, and then only to secure peace for the society. Private persons owe a duty of obedience to public authority and therefore are presumed to have an obligation to participate in a duly-authorized war (unless it is overwhelmingly clear that the war is unjust). It is an exaggeration of this idea of war as a public act that conceives of each member of a society individually as personally “guilty” for the public acts of that society.

[3] Though in the case of the Romans, especially in the later empire, citizenship was often not a requirement for armed service, but its eventual reward. In the Europe of the Middle Ages, the responsibility for fighting fell more heavily on some classes of society than others. In any event, none of these societies regarded war as the occupation of the whole community.

[4] Perhaps it goes without saying, but “peace” here should be understood not as an absence of conflict but rather as a constituent of the common good of the human community, as a harmony among peoples which makes possible the flourishing of all.

[5] See M H Keen, The Laws of War in the Late Middle Ages (London: Routledge & Kegan Paul, 1965), particularly chapter 8 on sieges. According to Keen, direct attacks on civilians following a siege (including rape and execution) were considered just on the grounds that the defenders of a under siege were, in principle, rebelling against the lawful authority of the prince under whose command the siege was laid. By remaining in the city, the civilians allied themselves in intention with the rebels and were therefore more or less subject to the same consequences of defeat. Note that this is an argument similar to one claiming that every member of a modern society at war is a legitimate target, though here the criterion of intention is made somewhat more explicit.

[6] On this account, civilian workers in munitions factories or those providing support services on military facilities are technically combatants and legitimate military targets—while they are on the job. While this point may be open to further discussion, I concur with the position that such workers cease to be combatants when they are not working. One entailment of this, of course, is that these workers cannot rightly be directly attacked in their homes, as was for example the strategy of British Bomber Command over Germany in the Second World War.

[7] We might call these groups of people natural non-combatants, but even here it is possible in particular circumstances for a member of any of these groups to become an actual combatant. A child can fire a rifle, an elderly woman can detonate a bomb. Should any member of these groups do such a thing they would, in virtue of that act, immediately become a combatant, and lose their natural immunity from attack.

[8] I will assume that the question of deliberate damage to public property must be treated differently, which is to leave open the possibility that intentional damage to public property might be justified where the same damage to private property would not. I do not intend to treat this question here.

[9] An interpretation of NCI that strips enemy non-combatants of their immunity in cases of supreme national emergency can only do so on utilitarian grounds, permitting apparent military necessity to trump NCI. And if this is so, it is not clear to me why military necessity should not always be a more important consideration, which of course vitiates NCI. Rather than adopt this specious position it seems to me better to qualify the Principle of NCI categorically, which requires a principled explanation for NCI in some circumstances but not in others.

[10] Any American teenager could be a good source for this sort of weapon.

[11] That some actions in this regard might be illegal is not itself an argument that non-combatants have a right to be immune to such attacks.

[12] Would it be possible for a “mild” electro-magnetic pulse to be applied to a population center in order to damage a variety of ordinary civilian machines?

[13] “Weapons” systems that disrupt power transmission grids without actually destroying the grid could be an example of this capability.

[14] The question of whether the civil authority would act justly to defend his community from a foreign power that seeks to recover what the first community unjustly stole is a different sort of question. Provided the foreign power is acting simply to recover what it lost, and perhaps to punish the offending community, but not to harm the innocent, it could be argued within the tradition that the offending community cannot justly defend itself.