The Roman Catholic Tradition1
Catholic Just War theory began as centralized government collapsed in Western Europe and barbarian migrations, Norse raiders, and feudal armies made for a Hobbesian world.
It evolved from classical thinkers such as Aristotle, Cato the Younger, Plato, Polybius and especially Cicero all of whom raised the question of when war is justSaints Ambrose (c. 340–397), Augustine (354–430), and subsequent Catholic thinkers developed Cicero’s (106–43 BC) notion of “Just War” into a highly influential theory.2 St. Thomas Aquinas’s (c. 1225–1274) Summa Theologicae is the most systematic, dividing the question of morality with respect to war into two issues. The first is jus ad bellum, when war is just; the second is jus in bello, how to fight justly. As the two are independent, it is possible to fight unjustly in a just cause, or justly in an unjust one. Some writers mentioned a third component, jus post bellum, justice after war, concerned with war termination and war crimes.
Catholic Just War theory rests on four assumptions. Independent states have the right to territorial integrity and political sovereignty. Together, states form international society. Force or threats by one state against another constitutes aggression, and aggression whether by state or non-state actors (Chapter 15), but nothing else, justifies a war of self-defense aided by any other willing states. Violation of a truce or treaty reopens the original conflict—not a new one.3
Jus ad bellum according to St. Augustine required meeting six requirements that have changed little in fifteen centuries. First, war must be the last resort. This requires that a government explore all other options before choosing war. But, as Michael Quinlan has written, perhaps thinking of several missed opportunities to stop Hitler at small cost before World War II, “To place military action at the very end of the line may mean invoking it only when matters have reached a desperate pass, and when its scale is larger than its robust use earlier might have entailed.
The passage of time is not neutral” (Elshtain 1992). The “last resort” may be an anachronism (Temes 2003) and certainly is difficult, probably impossible, to identify objectively and unambiguously. Ultimately, it is a matter of judgment. The modern interpretation dates from the Peace of Westphalia that ended the Thirty Years War4 and originated the modern state system. It rests on balance of power and the principle of non-intervention in the internal affairs of nations. It kept European wars small for a century and a half. The philosophical underpinnings were reinforced by the evolution of international law, which had its precursor in the Roman concept of ius gentium, the law of nations, but in its modern form traditionally is dated from the publication of Hugo Grotius’s Rights of War and Peace (1625), which also assumes that states have the right of self-defense.Second, the only just war is defending against actual or eminent aggression against oneself or an ally. War is just only if undertaken to redress a wrong already committed or to preempt one that is about to occur. Aggressors trying to appear just have claimed to be acting defensively, provoked others into attacking them, and issued ultimatums coupled with unacceptable demands. In September 1939, Germany dressed prisoners in Polish uniforms, killed them, and scattered them around their border to make the false claim that it was defending itself from attack rather than committing aggression against Poland. The result was World War II.
Third (Cicero’s major contribution), only a properly constituted government can wage war, and then only if it is openly declared in advance of hostilities. In 1941, Japan intended but failed to honor the letter if not the spirit of this requirement by having its declaration of war with the US delivered minutes before attacking Pearl Harbor. In fact, the attack came first due to delays in decoding. A more significant problem with this principle is that it rules out rebellion against a tyrant.5
Fourth, right intention requires that a war restore justice rather than advance self-interest.
Wars of aggrandizement, conquest, conversion, plunder, or punishment are unjust. Christian opinion during the Crusades had legitimated war on behalf of and authorized by God (well, the pope), but the Thirty Years War led to a consensus against spreading religion by war. Twentieth century wars re-emphasized the right of self-government and discredited imperialism. The difficulty is that some wars can both restore justice and advance national interests, and ruling out a war that does both may leave the injustice in place.Fifth, there must be a reasonable prospect of victory. Wasting life and resources is wrong if defeat is likely. However, war involves so many unexpected events and intangible factors that even careful estimates sometimes have proved wrong (Chapter 12).
Sixth, the forces employed must be proportionate and reasonable. The concept, which has its parallel in the force an individual can use against an assailant, allows the state to use more force in defense than the aggressor uses in attack, but not excessively so. The actual line between reasonable and excessive has proven impossible to define, so is a matter of judgment and debate in specific cases.6 This principle overlaps the guidelines of how a war should be fought, namely the principles of jus in bello.
Jus in bello, how to fight justly, has changed with time and technology and is likely to continue to do so. It encompasses two main issues. Proportionality concerns how much force is appropriate. Discrimination concerns the appropriate target of that force, requiring directing acts of war toward enemy combatants, not noncombatants caught in circumstances they did not create. Related concerns include economic sanctions (Chapter 15), prohibited weapons, and treatment of prisoners.
In feudal Europe, war was at least hypothetically an honorable undertaking fought chivalrously—although the code often was set aside when fighting heretics or non-Christians. Prisoners were at the mercy of their captors, sometimes killed, sometimes enslaved, sometimes ransomed.
Some weapons were unjust. For example, the twenty-ninth canon issued by the Second Lateran Council (1139 AD) reads, “We prohibit under anathema that murderous art of cross-bowmen and archers, which is hateful to God, to be employed against Christians and Catholics from now on.” Cynics claim that the real reason for the prohibition was that crossbows allowed commoners on foot to defeat noblemen on horseback. Now, poison gas, biological weapons, and nuclear weapons are banned, and efforts are being made to ban land mines.Proportionate collateral damage as an unintended result of a legitimate military operation is not just, but is justifiable— understandable may be a better word. Intentional attacks on noncombatants are prohibited. Those who make war materiel, but not those who make the normal necessities of life, are legitimate targets. The distinction could become very fine. Civilian shoemakers were exempt, but what about boot makers who supplied the army or shoemakers who did both? The distinction effectively disappeared with indiscriminant aerial bombing during the Spanish Civil War and World War II, partly to rationalize area bombing but more fundamentally because nations mobilized every resource for war, erasing the distinction between combatants and noncombatants. Capture in enemy uniform, or fighting or spying while dressed as a civilian, traditionally legitimates the death penalty.
Jus post bellum receives little attention in the classical literature beyond the principle that the victorious can punish but must not humiliate the vanquished. Both the purpose and the target of punishment remain unsettled. Possible purposes include deterrence, reform, restraint, and retribution. It is unclear whether to punish particular individuals or the aggressor state itself, and if the latter, if it might have unintended consequences. Many blame the humiliating punishment imposed on the Germans at Versailles for the outbreak of World War II. Of course, aggressors cannot be punished until they are captured.
Victory does not prove righteousness, nor does the righteous nation win every war.At least in Western nations, soldiers who intentionally kill noncombatants or prisoners, use banned weapons, or kill, torture, or mistreat prisoners are criminals.7 Clausewitz’s On War presages the concept of individual responsibility for war crimes, distinguishes means from ends, and provides guidance on conduct, raising the issue of the responsibility of the soldier. After World War II, individual Germans were found guilty and even executed for failure to resist illegal orders. On the other hand, Admiral Doenitz was not tried after Admiral Nimitz pointed out that the tactics he had used in the Atlantic were the same as those US submarines used against the Japanese in the Pacific. This raises questions of how terms are defined, the level at which responsibility is fixed, which orders which ranks should know to be illegal, and what individuals must do to resist illegal orders. Doing so risks immediate punishment by one’s own government; failing to do so risks punishment by some international tribunal long after the fact.
Recently, theorists such as Gary Bass and Brian Orend (2006) have focused on jus post bellum. The latter has proposed the following principles (which do not solve all of the problems but are a starting point for discussion):
· A state may terminate a war if there has been a reasonable vindication of the rights violated and if the aggressor is willing to negotiate terms of surrender that can include formal apology, compensations, war crimes trials, and rehabilitation.
· A state may end a war if just goals are unreachable at all or without using excessive force.
· A victorious state must apply the same level of objectivity and investigation into any war crimes its own armed forces may have committed.
· Only legitimate authorities can make and accept the peace terms.
· Punishment must be limited to those individuals directly responsible for the conflict.
· Truth and reconciliation may be more important than punishment.
· Terms of surrender must be proportional to the rights initially violated.