The recent war in Gaza has stimulated a lot of popular discussion about the moral implications of the use of so-called ‘human shields’, non-combatants who are in close proximity to combatants, either voluntarily or involuntarily. Much of this discussion has been very simplistic and transparently rhetorical. Nevertheless, there are interesting ethical issues arising in the context of asymmetrical warfare that we should be able to examine at a degree of abstraction from the contested facts.
I should perhaps note that I have never read anything on just war theory, so I apologize in advance if what I say below is old hat; all I know is that the points I make are not taken into account by popular commentary, even by leading philosophers like Michael Walzer. I hope writing in relative ignorance is okay for a blog post – my first ever, incidentally.
Let us begin with a reconstruction of what seems to be the underlying argument of many commentators. I will label it the Double Effect Argument, since it makes crucial reference to the Doctrine of Double Effect:
1. The Principle of Non-Combatant Immunity (NCI): Even in a just war, it is not morally acceptable to aim to kill or harm non-combatants.
2. The Principle of Combatant Non-Immunity (CNI): Killing, and aiming to kill, enemy combatants when (it is highly likely to be) necessary to achieve morally justified war aims is morally justified.
3. If enemy combatants intentionally place themselves among non-combatants (human shields) in order to abuse the Principle of Non-Combatant Immunity, they become morally responsible for any damage to non-combatants.
4. Thus, the presence of human shields makes no difference to the responsibilities of the party pursuing legitimate military goals: it continues to be justified in aiming to kill enemy combatants, even if it has the known side effect of killing and maiming human shields. This relies on what I will call the Narrow Doctrine of Double Effect (NDDE): it is permissible to knowingly cause harm as a side effect when it cannot be avoided while pursuing justified goals in the circumstances (which in this case are created by the enemy, not the agent). Bluntly: it is permissible to ignore harm to non-combatants, when a) it is not part of one’s aim or means and b) the enemy is responsible for placing the non-combatants in harm’s way.
Since I want to discuss the moral principles at a certain level of abstraction, I will talk about country A and militant group B below. I will assume that A has jus ad bellum against B; if it doesn’t, I take it jus in bello, justice in the conduct of war, is impossible or of little relevance. If B has a widespread practice of using human shields, the Double Effect Argument legitimizes quite a lot of damage to civilians of B by A. I’ll make four preliminary points, and then argue that the Double Effect Argument is far too permissive. The burden for justifying harm to human shields is much heavier than many commentators realize. Excuses for killing civilians do not come cheap.
1) High burden of justification
First, I want to emphasize that we are talking about terrible things here. We are talking about children burned to death, mothers losing both legs, fathers blinded, as a consequence of A’s action. We cannot be glib about justification on this issue.
2) The difference between hostages and human shields
Whether human shields are in the vicinity of fighters voluntarily or not, there is an important difference between them and hostages: human shields are at no risk from the fighters. Even if they are compelled at gunpoint to stay, it is not the case that were A’s troops to leave, the human shields would be at risk of being hurt. There are no demands to be met for their safe release, as in the case of hostages. This means that there is no need for A to interfere in the interest of the human shields, unlike in a hostage situation.
Note that civilians are used as human shields only if the combatants’ intention is to abuse NCI. If there are combatants in the vicinity of civilians, because it is the only shelter available in the battle zone, or because they are defending that very area, the civilians are not used as human shields. Theoretically, the difference is clear, and comes out counterfactually: in the latter cases, the combatants would prefer the non-combatants to be able to leave the battle zone. Practically, this is naturally difficult to tell, though as a rule of thumb, if A’s own military action prevents B’s non-combatants from leaving, they are probably not used as human shields. In actual fact, the use of human shields is likely to be very rare.
Note that CNI, as I have defined it, is very strict, as I think it should be. It does not legitimize killing enemy soldiers on leave, for example (unless that is necessary to achieve legitimate military goals, which is highly unlikely). It should certainly be brought to bear in all strictness to human shields cases. The stereotypical situation is basically this: B’s fighters are firing at A’s soldiers from among B’s non-combatants. We are assuming that A’s soldiers are on a legitimate mission. We may even assume that the mission is precisely to kill B’s fighters. Still, there is an important question of timing: is it really absolutely necessary to kill the fighters in question now, when they are among civilians? Must the military advance made this way, and must it made right now in order to reach the just war goals? Is it possible to open a passage for the non-combatants to leave? (If the fighters lay down their arms and mingle with the non-combatants, that is itself progress toward the just war goals.) Consequently, in every human shields situation, there is a weighty moral reason to wait as long as possible and offer a chance for the human shields to leave – in other words, to transform it into a non-human shields situation. It is morally wrong to kill combatants when it is not necessary to achieve just war aims, and it is doubly so to risk the lives of civilians when killing the combatants during the time they are in their vicinity is not absolutely necessary. (Obeying this principle may make wars last longer; this is itself a bad thing, but we must remember that a war in which jus in bello principles are strictly followed is a very different kind of war from the ones that we have actually seen.)
5) Intention, side effect, and alternative means
Suppose killing the B fighters among human shields right now is a military necessity. A is then faced with a choice of means. If A is a military superpower, it will have a large range of means at its disposal: snipers, mortars, artillery, missiles, bombs. It is here that the narrow doctrine of double effect is revealed as inadequate. For it is silent on the nature of the means involved. Compare the following scenarios:
Minimum: Two of B’s fighters are firing from a UN building with three hundred refugees they are using as human shields. It is a legitimate war aim of A to kill as many of B’s fighters as possible. To kill them, explosives must be used; heavy enemy fire prevents the use of snipers. The fighters are both in the east end of the building, as the live feed from A’s pilotless drone reveals. The commander in charge of A’s operation offers the non-combatants a safe passage to a Red Cross refugee camp outside the war zone, but they do not avail of the opportunity. A’s computer-and-satellite-guided artillery is very accurate (and the most accurate weapon available), and the commander waits for it to be available rather than using alternative means like missiles or mortars (which are far more inaccurate). The commander chooses the smallest available explosive payload, say 2 kg, and a shell is fired at the UN building. The two fighters die, as do four civilians closest to them, while 12 are injured.
Maximum: The same as above, except the commander chooses the most deadly explosives available in order to make sure that the two fighters are killed. The 100 kg shell is fired and obliterates the target. The two fighters die, along with 43 non-combatants and over 200 seriously injured.
The moral I’d like to draw from these two cases is the following. First, in terms of the narrow doctrine of double effect, these two cases are morally equivalent. In both cases, A’s intention is to kill the fighters, not any civilians. Killing civilians is not a means to any end of A’s, but risking it cannot be avoided in the circumstances (for which A is not morally responsible, under our assumptions). Hence, if the end is justified, A’s commander is equally justified in Minimum and Maximum. The narrow doctrine of double effect thus gives no guidance on the means one may use to kill one’s enemies.
Second, there is a significant moral difference between Minimum and Maximum. Indeed, I believe Maximum rises to the level of war crime, in spite of all the unlikely justificatory conditions (legitimate aim, military necessity, opportunity to leave, etc.) being in place. It is not just that the commander chooses the means knowing that there will be civilian casualties as a side effect. He chooses a means that ensures there will be maximal civilian casualties. This is a choice for which the enemy combatants can be held in no way morally responsible, even if they otherwise bear a significant responsibility for placing the human shields at risk. The magnitude of the risk, so to speak, is in the hands of A’s commander, not in the hands of B’s fighters. And it seems self-evident to me that A’s commander should, in these circumstances, minimize the risk to non-combatants. Otherwise A’s commander will intentionally place non-combatants at higher risk than necessary to achieve legitimate war aims. And when that risk is high enough, the moral difference between aiming at the death of civilians and causing their death as a side effect evaporates.
This suggests the following principle to replace NCI:
The Principle of Non-Combatant Protection (NCP)
Jus in bello requires aiming to protect the non-combatant population from war damage as far as possible within the pursuit of morally legitimate military goals.
NCP is stronger than NCI, since it requires not only the absence of intention to harm but also the presence of intention to protect. A commander who obeys NCP will choose the means that is least risky for the non-combatants, even when it makes success in the military goal less likely. (I suppose a weaker principle would suffice to distinguish between Minimum and Maximum, but NCP seems independently plausible.) Gross violations of NCP may be war crimes, even if they obey the letter of NCI.
Third, and relatedly, in these cases, as in most real-life cases, there is a trade-off between risk to own troops and risk to non-combatants. Firing high-caliber weapons from a distance beyond the enemy’s reach minimizes risk to own troops while maximizing the risk to non-combatants. This seems morally unacceptable. In terms of virtue, it is cowardice. It is very difficult to say where the balance lies here, but at the very least, jus in bello, not to mention military virtue, requires that the commander take the risk to non-combatants into account in deliberating how to proceed, not just risk to own troops.
As I said at the beginning, these thoughts are inspired by the conflict in Gaza, and in particular attempts to morally justify the large-scale killing and maiming of civilians that has taken place. I believe the burden of justification is significantly higher than many commentators claim. Whether it is nevertheless met by either side is a factual rather than philosophical question, so there is no point in debating it here. Let me just register my incredulity.