War Crimes

Although the notions of crimes against humanity and genocide may be comparatively recent, the concept of war crimes as a restraint on the military is of much older origin. Virtually every recorded civilization placed some limitations on the conduct of its own warfare, and violations of such rules could therefore be considered war crimes. In the Egyptian and Sumerian wars of the second millennium B.C.E., there were rules defining the circumstances under which war might be initiated. In ancient China it was forbidden in wartime to kill wounded enemies or to strike elderly armed opponents. The Chinese philosopher Sun Tzu wrote in The Art of War (400 B.C.E.): "Treat the captives well and care for them. All the soldiers taken must be cared for with magnanimity and sincerity so that they may be used by us" (Friedman, p. 3). Similar restrictions on killing the wounded, ordinary citizens, women, children, or prisoners were expressed in Hindu literature of the fourth century B.C.E., in Babylonian texts, and in the Bible (Deut. 20).

The Greeks and Romans introduced further notions of humane and civilized treatment of noncombatants in war. Plato wrote in his Republic that war among the Hellenes should have as its end "friendly correction," and not destruction of the enemy. The Romans developed the concept of the "just war" that alone warranted resort to force. Truces, safe-conduct passes, and armistices were respected, and cease-fires were agreed upon so that the dead might be buried. Poisoned weapons were prohibited. This is not to say that the Greeks or Romans did not engage in barbarous acts in time of war. But the development of rules of restraint, although frequently violated, established the principle that limits had to be placed on acts of war—a notion that Christianity was to carry forward over the coming centuries.

In the early Christian era, observance of the Christian principles of pacifism and nonresistance eventually gave way to ferocious efforts to defend Christendom and expand its boundaries. St. Augustine (354–430) and St. Thomas Aquinas (1225–1274) developed the just-war doctrine, arguing that wars by a Christian sovereign to spread and protect the true faith against attack by outside enemies were justified. The early church fathers had insisted that soldiers who killed even in a just war should do penance, and they warned against pillaging and slaughter. Later, ecumenical councils of the church passed various decrees establishing a "Truce of God," when all fighting was to cease, and tried to arrange cease-fires between Christian princes during the Crusades.

Beginning in the fifteenth century, two other developments contributed to the establishment of rules of war on an international basis: (1) the chivalric code of honor took shape, limiting the weapons and methods that could be used in combat; and (2) merchants insisted that unlimited pillaging and destruction in wartime ought to be restrained. The chivalric code applied across national borders and was founded on natural law, limiting even princes in their capacity as knights and soldiers (Keen, p. 50).

Scholastic teachers, jurists, and theologians reexamined and systematized the laws of war as derived from classical Greek and Roman practice, Christian doctrine, contemporary practice, and chivalric codes. Francisco de Vittoria (1485–1546), a Spanish professor who lectured on Thomist philosophy in Paris and Salamanca, examined the moral and legal problems of the Spanish conquests against the Native Americans in the New World in his work on the law of war. He concluded that "it is never right to slay the guiltless, even as an indirect and unintended result, except where there is no other means of carrying on the operations of a just war" (p. 179). Other important sixteenth- and seventeenth-century writers on the laws of war were Balthazar Ayola, judge advocate of the Spanish armies in the Netherlands; Francisco Suarez; and Alberico Gentili.

The most systematic and comprehensive work on the laws of war was that of the Netherlander Hugo Grotius (1583–1645), who served in many important positions in the Dutch government, including a term as attorney general. In 1625 he published a three-volume work titled The Law of War and Peace , which brought together classical and medieval thought on the restraints on war and sought to reconcile Christian dogma and the actual practice of contemporary states in wartime. Grotius attempted to discover what the rules of international law were, using the acts of generals and soldiers as the basis for his search. Writing at the beginning of one of the most ferocious and bitter wars of European history, the Thirty Years' War (1618–1648), Grotius proceeded on the assumption that the experiences and actions of armies in war were not improper deviations from a theological norm. Rather, they were the expressions of a natural order, whose principles he could determine.

Grotius sought to explain what that natural law was. If war does have rules that all states obey (or should obey), then deviation from those rules should become a crime—a war crime, as the twentieth century would call it. Some seventeenth-century Christian princes took Grotius's rules seriously. Gustavus II Adolphus of Sweden carried a copy of Grotius's book with him everywhere, established strict rules against attacking hospitals, churches, schools, or the civilians connected with them, and severely punished those of his own soldiers who disobeyed the rules (Wedgwood, pp. 261, 265). Other generals either did not or could not control their men, and mass destructions and pillage took place frequently. In the rare cases when soldiers were punished for such deeds, it was not because they had committed a war crime—which had no meaning at the time—but because they had committed murder or rape under circumstances that the commander could not overlook.

The rise of the nation-state in the eighteenth and nineteenth centuries and the decline of the church's moral authority led to more concrete efforts to define and codify the laws of war whose violation would constitute a war crime.