Inherent in modern war-making practice is the conviction that there is a significant moral difference between killing innocent civilians in an attack such as that on the World Trade Center or on a bus filled with college students and killing noncombatants during a military response to such an attack. This conviction is clearly demonstrated in a myriad of Israeli reprisals against Palestinian terrorist groups such as Hezbollah and in the US war in Vietnam, Kosovo, Afghanistan, and Iraq. It is reflected, as well, in the language used to describe the innocent deaths, the value laden term "terrorism" in the case of the former, and the morally neutral term "collateral damage" in the latter.War, even as a response to terrorism is rule governed. According to Just War Theory and a myriad of international agreements and treaties, war is evaluated according to whether established criteria are satisfied. One of the most important rules of war is the legal and moral prohibition against the targeting and killing of innocents, i.e., the criterion of discriminating and affording of immunity to noncombatants - the Criterion of Discrimination. Since noncombatants are neither directly nor indirectly involved in the prosecution of a terrorist attack or of a war, they have done nothing to warrant a forfeiture of their immunity. Consequently, to kill noncombatants to further some goal or objective whether political, religious, or social, even if for a just cause, is not an act of war but of murder and fundamental to our understanding of terrorism. That is, the Criterion of Discrimination is integral in differentiating war from terrorism and killing in war from murder. Acts of terrorism, unlike acts of war, knowingly harm and kill noncombatants.
Foundational to the concept of collateral damage is the Doctrine of Double Effect (DDE). First developed by Catholic casuists during the Middle Ages, the DDE morally differentiates the intended effects of an act from those that are unintended, though foreseen. Further, by focusing upon the moral significance of intention and its relevance to moral agency and responsibility, the DDE morally distinguishes killing as an unintended, secondary effect - - collateral damage - - from murder, claiming only the latter as absolutely prohibited. Consequently, the Criterion of Discrimination is preserved and, if intention is withheld, killing noncombatants is morally permissible. Herein, then, lies the alleged crucial moral distinction between the acts of the terrorist and of those who respond to terrorism (responders) and between murder and collateral damage. Terrorists are acting immorally and are morally culpable1 and liable2 for their actions because they intend the noncombatant deaths in their attacks. They are committing murder. Those who respond to terrorism, however, claim only to be targeting the terrorists, or the regimes that support terrorism, and any noncombatant deaths that occur, though foreseen, are, it is alleged, the unfortunate, unintended, by-product of a "moral act" of combating terrorism. Such killing is not murder but collateral damage. Consequently, responders are acting morally and are non liable and non culpable for the noncombatants they kill.
The DDE justification is not just the stuff of theoretical philosophers and theologians. Tragically, it has real world application and, with the "New Warfare" strategy of the last decade - standoff "precision" missile and aircraft attacks - the DDE has become an important justificatory tool of US war fighting. While the instances of collateral damage are myriad, I will consider, as representative, the April, 8, 2003 US attack on the al-Sa'ah restaurant. According to American intelligence sources, Saddam Hussein and his two sons, Uday and Qusay, had been meeting with key aides in a bunker deep beneath the al-Sa'ah restaurant located in the densely populated Mansour district of Baghdad. Shortly after 3pm, an American B1 aircraft dropped four satellite guided bunker-buster bombs on the restaurant. Unfortunately, all four bombs missed their target, destroying homes and turning at least fourteen innocent people, three of them children, into what the US military refers to as a "pink mist." If Saddam and his sons were present at the restaurant at all, they were not harmed in the bombing. The innocent deaths were dismissed as collateral damage and no one held responsible or accountable for this tragic loss of life.
There are a number of important observations regarding this attack that are morally relevant to a DDE justification. First, the obvious. The Iraqi civilians, living in the proximity of the restaurant, had done nothing to warrant liability - a forfeiture of their immunity. They were innocent, noncombatants. Second, consider a hypothetical. If the Iraqi civilians had become aware that an attack was immanent and could not escape, would they have been within their rights to respond defensively - to shoot down the aircraft (killing the pilot) in self-defense. I think the answer is clearly that they would. Human beings do not loose their right to defend themselves because others have deemed their deaths to be inconsequential - necessary for some greater good. It is not the case, by the way, as a consequence of now being threatened by an Iraqi defensive response, that the pilot could have morally targeted and killed the Iraqi defenders - claiming self-defense. The Iraqis do not forfeit the very right they are justified in asserting. What is irrelevant in this hypothetical is whether the pilot has agency, whether the threat to the Iraqis is directly intended or unintended, and whether the Iraqi deaths are the primary or secondary effect of the act of bombing the restaurant. In other words, what is irrelevant is the application of the DDE.
The fact that the Iraqis may justifiably shoot down the aircraft in self-defense is legally and morally significant. It indicates that the pilot's right to life and claim against others has been forfeited or overridden. Clearly, the pilot's liability is a consequence of his bombing (or threatening to bomb) the restaurant and killing (or threatening to kill) the Iraqis. Since acting morally and permissibly ought never warrant such sanctions, i.e., being the victim of the justifiable use of violence/deadly force in self-defense, the Iraqi's right to kill the pilot indicates the failure of the DDE to do the moral work alleged, that is, to render the bombing of the restaurant morally and legally permissible and the deaths of the Iraqis trivialized as collateral damage.
Also of moral relevance in many such incidents of collateral damage is that the responders do not merely foresee the possibility that, despite reasonable preventive precautions, sometimes things go awry and non-combatants will be killed. The responders kill innocents knowingly and with free will and consent in order to achieve the goal or objective of ending terrorism (or eliminating the Iraqi leadership). In such cases, therefore, killing noncombatants is not accidental, but what I will term an "act of collateral violence." That is, an act, motivated by military necessity, in which noncombatants are harmed or killed, perhaps not with direct intent nor as the primary goal or purpose of the act, but, nevertheless, knowingly and with as high a degree of probability as is the harming or killing of the terrorists. Consequently, the fact that a responder claims only to be targeting the terrorists (or Saddam and his sons) does not absolve him of causal and moral responsibility.
Where the DDE justification goes wrong, then, is in the moral importance it assigns to the directing of intent. That is, it relies exclusively upon the intended effect of the act as proclaimed by the actor as the crucial moral consideration for determining the permissibility and moral value of an act, rather than taking into account the entire set of foreseen probable effects. Consequently, only the intended "good effect" becomes morally relevant, and the foreseen evil effect - now termed "collateral damage" - becomes somehow abrogated and moral responsibility for the innocent deaths somehow diffused. The DDE justification fails because morality requires more than merely a proclamation of good intent.
A DDE justification in such cases and the alleged distinction between terrorism and a collaterally violent response to terrorism, between the attacks of 9/11 and the bombing of the al-Sa'ah restaurant, is misguided and merely a pretense or rationalization for retaliation and revenge. Both acts knowingly kill noncombatants to achieve some goal or objective. Both terrorists and responders violate the right to life of their innocent victims and fail to fulfill their obligation to respect such rights. Consequently, there is no moral difference between acts of terrorism and of collateral violence. They are morally equivalent. Neither are acts of war but of murder. Neither the terrorists nor the responders in such cases are combatants but brigands and murderers. With the civilian death toll in Iraq estimated at over 654,000, a recognition that collateral damage is nothing more than a rhetorical contrivance that trivializes the murder of innocent human beings, should be of moral concern to us all.