A body of customs, practices, usages, conventions, protocols, treaties, laws, and other norms that govern the commencement, conduct, and termination of hostilities between belligerent states or parties.
Frequently violated and sometimes ridiculed, the rules of war have evolved over centuries. They distinguish nations whose armed forces respect some minimal standard of human decency from terrorists, marauders, and other outlaws who use illegal and unrestricted methods of warfare to achieve political, economic, or military objectives.
The modern rules of war trace their origins to the chivalric practices of medieval Europe. Feudal knights were bound by the law of
chivalry, a customary code of conduct that could be enforced in local courts throughout western Europe by a military commander of any nation. Premised on notions of justice and fairness, the law of chivalry gave birth to the distinction between soldier and civilian and the idea that women, children, and older persons should be shielded from the bloody fields of combat. The Roman Catholic Church also influenced the development of these rules, differentiating between just and unjust wars and denouncing certain weapons as odious to God.
CODIFICATION of the rules of warfare began in the nineteenth century. In 1862 President ABRAHAM LINCOLN commissioned Francis Lieber to draft a code of regulations summarizing the laws and usages of war. A year later, Lieber submitted a draft that the EXECUTIVE BRANCH promulgated as General Orders No. 1, entitled Instructions for the Government of Armies of the United States in the Field. Known as the Lieber code, this systematic articulation of the rules of war remained the official pronouncement of the U.S. Army for more than a half a century. It addressed the concept of military necessity, detailed the rights of prisoners, noncombatants, and spies, and discussed the use of poisons, unnecessary violence, and cruelty.
In 1864 the codification movement took on an international flavor when 12 nations signed a Convention for the Amelioration of the Condition of the Wounded in Armies in the Field, 129 Consol. T.S. 361, the first of a series of Red Cross initiatives for this purpose. In 1899 the United States, Mexico, Japan, Persia (now Iran), Siam (now Thailand), and 19 other nations, including all major European powers, signed a Convention with Respect to the Laws and Customs of War, 187 Consol. T.S. 429, an initiative that followed the broad outlines of the Lieber code and also addressed the relationship between an occupying power and noncombatant civilian inhabitants. In 1914 the Lieber code was replaced by an army manual entitled The Law of Land Warfare, which continued in the early 2000s to be enforced.
Codification of the international rules governing land, sea, and air warfare accelerated following the conclusions of World Wars I and II, the KOREAN WAR, the VIETNAM WAR, and the many other hostilities that took place during the twentieth century. In addition to building upon the principles previously established, this period witnessed the creation of several new concepts, including certain categories of WAR CRIMES, such as crimes against peace and crimes against humanity.
Crimes against peace are committed by persons who plan or wage aggressive wars. Crimes against humanity are committed by persons who knowingly participate in the deportation, enslavement, persecution, or programmatic extermination of certain segments of society during times of war. Soldiers, military leaders, political officials, members of the judiciary, industrialists, and civilians are all subject to prosecution for violating any of these rules of war.
Leaders and officials who wage aggressive war, disregard the territorial or political independence of another state, or violate the express terms of a peace settlement may be prosecuted as war criminals under the United Nations Charter. They may also be prosecuted under the Nuremberg principles, derived from the NUREMBERG TRIALS after WORLD WAR II in which the Allied powers tried 24 leading Nazis for an assortment of war crimes, including crimes against peace and crimes against humanity. The Allies later prosecuted more than a hundred German civilians, including industrialists, doctors, and judges, who were enlisted by the Nazis to further their system of terror.
The rules of war do not apply to every act of hostility against an established government. Openly declared wars between sovereign states clearly implicate the rules of war. When the belligerents do not issue formal declarations of war, the legal status of a military conflict becomes murky. Isolated acts of TERRORISM or subversion, however, neither constitute acts of war nor create a state of war. Such acts are normally punishable under the criminal laws of the country in which they are perpetrated.
Wider internal disturbances within the territorial borders of a country are more difficult to classify. When such disturbances begin, the ruling government is apt to classify them as riots or rebellions, while those who cause the disturbances are likely to classify them as acts of civil war. INTERNATIONAL LAW provides no definitive classification for such hostilities. But subversive groups that acquire sustained control over substantial territory and win measurable domestic support are more likely to receive the benefit of the rules governing warfare than are small bands of insurgents whose seditious efforts are stifled and repelled.
Even when a state of war indisputably exists, the rules of war do not apply to all combatants. Regular land, air, and naval forces are typically governed by the rules of warfare. Irregular armed forces, such as guerrillas and other insurgents, are governed by these rules only when they carry their weapons openly, wear uniforms clearly displaying a recognizable emblem or insignia, conduct their operations in accordance with the laws of war, and are commanded by a superior who is responsible for subordinates.
The point of these rules is not only to distinguish combatants from noncombatants but to distinguish conventional soldiers from hired assassins, spies, and mercenaries who circumvent the customs of war in order to accomplish an end that could not be achieved by regular armed forces. Because assassins, spies, and mercenaries do not comply with the rules of war, their captors need not either. Similarly, combatants who attempt to flout the rules...