The doctrine of noncombatant immunity was developed in the Catholic tradition and in international and humanitarian law. St Thomas Aquinas provided the classic treatment of the just war in the Catholic tradition in his Summa Theologiae where he laid down the basic conditions for the justice of war: appropriate authority, just cause, and right intention. He did not develop a doctrine of what we now call ‘non-combatant immunity’, which was developed later. The rules governing the immunity of the innocent from attack were first codified by jurists: later, theologians took up and developed the doctrine.
In its early stages the principle was expressed as the immunity of “innocents”. This term made sense in terms of the ancient notion of “punitive” war; a just war was waged to punish the guilty. Therefore the use of force could be justified against the guilty, but not against the innocent. In later developments, which included the abandonment of the punitive theory, the designation “innocent” was replaced with “noncombatant.” The criterion for immunity became: no direct involvement in combat. The argument is that one who is not a direct agent of deadly force may not be repelled by deadly force.
Rights of noncombatants
The basic point is the right to life. According to the ethics of war, those who, like soldiers, engage in the use of deadly force, by that fact, accept a limitation of their right; they may be killed in lawful combat. Noncombatants, however, by definition do not engage in such use of force; they retain their right to life and may not be attacked. Noncombatants are now protected by international law and humanitarian law, as defined in Protocol 1 of the Geneva Convention. The humane treatment of noncombatants is also required by the Catholic Church, as for example in the Catechism of the Catholic Church.
Some ethicists have argued that noncombatant immunity is merely a “conventional” rule; that is a rule which can be suspended by one side if it is first broken by the other. But surely if one side does wrong this does not justify the other’s doing wrong; the convention argument simply eliminates ethics from war.
Another argument is that if our “cause” is just, we would be acting contrary to justice is we did not pursue that cause in the most effective way, even if this entailed killing noncombatants. But this gives absolute priority to “our” cause; the rights of the noncombatant victims are simply ignored. The argument is based on calculation of consequences and the only consequences that count here are the benefits for those pursuing their cause.
The principle of noncombatant immunity is sometimes interpreted to mean that what it forbids is killing a disproportionate number of noncombatants. The implication is that it would be morally acceptable to kill some noncombatants, but wrong to kill too many. This is a misunderstanding of the meaning of proportionate. Proportion concerns the relation of the degree of force used in attack to that used in defence against the attack; it does not refer to the number of victims killed in relation to the positive outcomes achieved.
It cannot be argued that if a nation is defending a great value, a correspondingly great number of noncombatant victims would be a proportionate loss and therefore morally justifiable. The deaths of noncombatants caused by the saturation bombing of World War II and the nuclear attacks on Hiroshima and Nagasaki cannot be justified by appeals to the good of ending the war.
When the force is excessive it is said to be “disproportionate”. When the force is not aimed with sufficient precision at the source of the attack and thus may harm noncombatants, it is said to be “indiscriminate.”
To explain the meaning of proportion we can invoke the analysis of the moral justification of the use of force in the case of self-defence as this has been understood in the Catholic moral tradition. The question is what would be an appropriate response when one individual or group attacks another. The one who is attacked could reply to the attack by moving out of range. If this is not possible, the one under attack would be morally justified in using force to the degree necessary to repel the force of the attacker.
If the force used by the attacker reaches a level of intensity where it constitutes a threat to the life of the one attacked, the one who is attacked may use proportionate force to repel the attack; he may so act even if this results in the killing of the attacker. If a degree of force is used that is disproportionate to the force used by the attacker, the actions of the defender can no longer be considered defence and must be recognised as a direct attack. If the defender, now become an attacker, uses a degree of force that results in the death of the other, he is guilty of that death.
Just defence in Gaza?
Hamas’s firing of rockets into Israel is indiscriminate; it violates the requirement of noncombatant immunity and so is immoral. Israel has used “iron dome” technology to repel the rocket attacks by Hamas; this is clearly proportionate and so legitimate. Those directly involved in firing the rockets may be directly attacked by Israel; this is legitimate defence. Those who are not so involved may not be attacked.
It cannot be argued, as it was recently by one commentator, that because the people of Gaza elected Hamas they may be justly attacked. Whatever may be thought of this argument, the many children in Gaza were certainly not responsible for the actions of Hamas.
Israel also seeks legitimately to eliminate Hamas’s launching sites and tunnels. But if, in so doing, Israel uses a degree of force that is disproportionate with respect to that aim, or uses force in a way that is indiscriminate, and thereby causes the death of noncombatants, Israel is morally guilty of those deaths. It is not sufficient to argue that Israel does not directly target civilians. Other means should have been used for this purpose even it meant higher casualties for Israel.
Professor Brian Johnstone is a Redemptorist priest who has taught moral theology for many years at Catholic University of America and at the Alphonsian Moral Academy in Rome.