Posted on March 12, 2019 at 6:30 AM
This essay received an honourable mention in the 5th Annual Oxford Uehiro Prize in Practical Ethics, Graduate Category.
Written by University of Oxford DPhil student, Robert Underwood.
Lt. Col. Bob Underwood is a U.S. Army officer and a Fellow in its Advanced Strategic Plans and Policy Program. He is pursuing a DPhil in Philosophy at the University of Oxford and will assume command of 1st Squadron, 4th Cavalry in the summer of 2019. The opinions expressed here are his own and do not reflect the official position of the U.S. Army, the Department of Defense, or the U.S. Government.
Killing in war eliminates threats but also plays a part in influencing the decisions of other persons beyond those we might kill. This suggests that killing in war has a communicative function, and that the message is an important consideration that can feature in the balance of reasons to kill some but not others in war. This is true provided combatants can permissibly kill some as means to communicate to others. I argue that just combatants, those that fight for just aims, can permissibly kill to communicate and that unjust combatants cannot. This is a new reason to revise our intuition that combatants on both sides hold equal rights to kill, the so-called moral equality of combatants (MEC).
Many argue that reprisals and terrorism are morally different than justified killing in war precisely because they are communicative. Taking such arguments seriously suggests a central, and familiar, objection to the communicative function I am seeking to justify. Namely, it uses the person killed as a means to influence others. Killing that communicates is essentially, or at least significantly, opportunistic and, other things being equal, opportunistic harm is harder to justify than eliminative harm. Also, most argue that killing combatants in war is mostly eliminative because it removes the threats they pose or their contribution to threats of harm. So, the scope of the central objection may be quite wide, for even killing that has an immediate defensive, and therefore eliminative, purpose may also be intentionally communicative and thus opportunistic. In fact, it is best to see killing in war as a range of cases in which the same act of defensive harm has an eliminative function and an opportunistic function. These functions are on a spectrum where the eliminative and opportunistic purposes can invert. To see this, consider some cases using a Tank Crew.
Terror Tank: A Tank Crew of 4 just combatants, fighting in a justified war necessary to stop an ongoing genocide of Victims, is on a mission to protect a local village. Cresting the ridge, Tank Crew surmises that a platoon of 30 Enemy Soldiers is in the village and threatens to kill 5 Victims unjustly. Tank Crew knows that demonstrating the awesome power of their tank cannon will cause the Enemy to panic and retreat, and this is the only means of saving the 5. Tank crew kills a Bystander, on the road to the village, because this provides the best demonstration of the awesome power of their tank, saving the 5 Victims.
Tactical Tank: As in Terror Tank but Tank Crew kills 1 Soldier, an unjust combatant on the road to the village, because this provides the best demonstration of the awesome power of their tank, saving the 5 Victims.
Tactical Options: As in Tactical Tank. Tank Crew sees two Soldiers, Bob and Joe, patrolling opposite ends of the village looking for other Victims. Tank Crew kills Bob because he is closer to the platoon and thus provides the best demonstration of the awesome power of their tank, saving the 5 Victims.
The crews in Terror Tank, Tactical Tank (TT), and Tactical Options (TO) avail themselves of an opportunity present in the circumstances. However, the killing in Terror seems intuitively impermissible, and the fact that Crew both lethally harms and uses Bystander as a means grounds this intuition. The killings in TT and TO seem intuitively permissible. But this may seem puzzling on reflection because the Crew also lethally harms and uses Soldier as a means in each case.
There are at least four justifications Crew could offer in TT and TO. First, Crew could respond that killing of the soldier on the road has an eliminative justification. But this seems an inadequate solution because TT and TO suggest there is a spectrum between eliminative and opportunistic functions. Reducing a combatant’s rights against opportunistic harm to their liability to eliminative harm seems both too simple and unfair. Especially when Crew intends that opportunistic effect as a means. In both cases, Crew acts for the reasons derived from the opportunistic function of the harm and not the eliminative function.
Second, Crew could respond that Soldier is liable to be opportunistically harmed in just this way. Soldier’s liability to be harmed and used could follow from his comparative responsibility, however slight, for the ongoing genocide. This response, following Jeff McMahan, endorses a comparative basis of liability to killing in war that is controversial. Some reject it outright and others raise concerns in the context of justifying opportunistic harms. On this view, Soldier’s rights against being lethally harmed and used as a means should be forfeit only if and because his actions make these rights forfeit. Also, even if we agree with a comparative basis for liability, we might still worry that his comparative liability is sensitive to the good effect intended by Crew.
Suppose then, for the sake of argument, he is not liable to be killed opportunistically.
Crew could still offer a third response: the opportunistic effect could be a side effect, one Crew foresaw and hoped would come about, but did not intend. TT and TO are thus examples of Frances Kamm’s doctrine of triple effect. Kamm’s distinction is controversial because we must believe that Crew intended the good effect, saving the 5, without intending the means to that effect, killing the Soldier. But this is also a plausible explanation of the difference between Terror and TT. Triple effect cannot, however, explain our intuitions about Crew in TO. Once there are two options, kill Bob or Joe, we change the relationship between Crew and their intended actions. If Crew chooses an option that has an effect, over other options that lack that effect, and all else is equal, then Crew intends that effect.
Crew could finally offer a fourth response in TT and TO: Crew can extend the permissibility of the eliminative harm to the opportunistic harm. This would be an adaptation of Kamm’s “Principle of Secondary Permissibility (PSP).” TT and TO require adapting the PSP because Crew is not minimizing the harm inflicted on the soldiers they kill. Rather, Crew permissibly minimizes the overall harm through means that are no worse for the persons that are harmed. So, when just combatants have a liability justification for eliminative killing, then just combatants can extend this permissibility to the opportunistic effect. Since it would be permissible to kill these unjust combatants eliminatively and killing them opportunistically is at least no worse for them, the minimizing of the overall harm inflicted by saving the 5 innocent Villagers justifies the opportunistic harm. The first three responses seemed inadequate. But, the PSP meets the central objection because it relies on the grounds that made Solder’s rights potentially forfeit – minimizing unjust harms. The PSP is also apt to the spectrum between eliminative and opportunistic purposes. Minimizing the overall unjust harms justifies the messages just combatants send when they eliminatively kill some and not others.
Just combatants, then, can justify killing to communicate so long as their intentions are aligned with the good aim that justifies an act, killing one to communicate to others, that is pro tanto wrong. For those who think our intentions and motivations in action do affect their permissibility, then choosing an option in order to produce some good effect not only involves intending that effect but seeks to justify that act in terms of its good effects. This implies Crew must actually intend the good in order to appeal to the PSP. That is, to see their actions and choices as leading to the good effect and not bringing it about as an unintended, merely foreseen good side-effect.
If I am right that just combatants can only meet the central objection in its strongest form by intending the good, then intending the just aim is morally required for permissible use of eliminative harms that communicate. Therefore, the communicative function of killing in war is a mark against the doctrine of the MEC. Just combatants can appeal to the good effects of the message sent by killing some to communicate to others. This is not the case for unjust combatants. The eliminative harms unjust combatants inflict on just combatants will normally have a communicative function. Killing some to influence others is a central rationale for killing in war, this is often enough true of those who fight for unjust aims. In fact, the only option for unjust combatants seems to be making the eliminative harm they inflict worse. For, if they were to intend their aims in the practically rational way required for just combatants to justify the communicative function of killing in war, then they would intend both the wrongful act and the bad aim of the unjust war. Unjust combatants either employ eliminative harms that have an unjustified communicative function, or, they intend the wrongful act and the bad aim. On both scores, we have good reason to doubt that just combatants and unjust combatants have morally equal rights to kill.
Frowe, H. and G. R. Lang (2014). How We fight : ethics in War. Oxford, Oxford University Press.
Haque, A. A. (2017). Law and morality at war. Oxford, Oxford University Press.
Kamm, F. (2000). “The Doctrine of Triple Effect.” Proceedings of the Aristotelian Society 74: 21.
Kamm, F. M. (2007). Intricate ethics : rights, responsibilities, and permissible harm. New York, N.Y. Oxford, Oxford University Press.
Kamm, F. M. (2016). The moral target : aiming at right conduct in war and other conflicts. Oxford, Oxford University Press.
Lazar, S. (2015). Sparing civilians. New York, Oxford University Press.
McMahan, J. (2011). “Who is Morally Liable to be Killed in War.” Analysis 71(3): 544-559.
McMahan, J. (2012). “Individual Liability in War: A Response to Fabre, Leveringhaus and Tadros.” Utilitas 24(2): 278-299.
McMahan, J. (2016). The Limits of Self-Defense. The Ethics of Self-Defense. C. Coons and M. Weber. New York, NY, Oxford University Press.
Pincione, G. and F. M. Kamm (2016). “The Trolley Problem and Aggression.” 32(2): 1-17.
Quinn, W. (1989). “Actions, Intentions, and Consequences: The Doctrine of Double Effect.” Philosophy and Public Affairs 18(4): 334.
 Quinn, W. (1989). “Actions, Intentions, and Consequences: The Doctrine of Double Effect.” Philosophy and Public Affairs 18(4): 334.
 I intend the Tank Crew to be in the same epistemic and intentional status as Jeff McMahan’s Bomber Crew in “Self-defense Against Justified Threateners.” Cf. Frowe, H. and G. R. Lang (2014). How We fight : ethics in War. Oxford, Oxford University Press.
 McMahan, J. (2012). “Individual Liability in War: A Response to Fabre, Leveringhaus and Tadros.” Utilitas 24(2): 278-299. Pg. 299. Cf. McMahan, J. (2011). “Who is Morally Liable to be Killed in War.” Analysis 71(3): 544-559, McMahan, J. (2016). The Limits of Self-Defense. The Ethics of Self-Defense. C. Coons and M. Weber. New York, NY, Oxford University Press.
 Lazar rejects a comparative basis of liability in Sparring Civilians. Lazar, S. (2015). Sparing civilians. New York, Oxford University Press. Adel Haque raises concerns about McMahan’s account on the grounds that liability to eliminative harm cannot entail liability to opportunistic harm. Haque, A. A. (2017). Law and morality at war. Oxford, Oxford University Press.
 I am indebted to Jeff McMahan for the suggestion that the case is an example of Kamm’s principle. Cf. Kamm, F. (2000). “The Doctrine of Triple Effect.” Proceedings of the Aristotelian Society 74: 21, Kamm, F. M. (2007). Intricate ethics : rights, responsibilities, and permissible harm. New York, N.Y. Oxford, Oxford University Press.
 Kamm, F. (2000). “The Doctrine of Triple Effect.” Proceedings of the Aristotelian Society 74: 21.
 Kamm, F. M. (2007). Intricate ethics : rights, responsibilities, and permissible harm. New York, N.Y. Oxford, Oxford University Press. Pg. 171
 Kamm has made similar adjustments in applying the PSP. Cf. ibid., Kamm, F. M. (2016). The moral target : aiming at right conduct in war and other conflicts. Oxford, Oxford University Press, Pincione, G. and F. M. Kamm (2016). “The Trolley Problem and Aggression.” 32(2): 1-17.