Laws of War. The idea of laws of war is ancient and ubiquitous; fragmentary indications appear in the records of most known civilizations and cultures. The inter national laws of war as known today, however, are of relatively modern and regional origin. The Roman concept of a law of nations (
jus gentium), persisting through Europe's medieval centuries and ingesting elements of Christian “just war” doctrine, chivalric honor, military professionalism, and commercial prudence, produced by the sixteenth century a body of customary principles and rules purporting to show how to judge whether a war was justified (
jus ad bellum) and how wars should ideally be conducted (
jus in bello). Reality, always falling short of the ideal, became so horrific in the Thirty Years' War that the Dutch Christian‐humanist‐ diplomat Hugo Grotius (1583–1645) was prompted to publish in 1625
De jure belli ac pacis (
Concerning the Law of War and Peace), usually considered the first definitive text on international law. Accepting war as a legitimate political institution, he maintained the just war thesis that it should not be begun without good cause, and argued with moral fervor that war could, indeed should, be conducted with more moderation than was usually the case. When, in the later nineteenth century, modern international law crystallized and the customary laws of war began to be codified, Grotius's visions of international community and universal standards renewed the respect for him that persists today.
The temporary eclipse of jus ad bellum did not mean that jus in bello was neglected. Men of honor took it seriously. Self‐respecting commanders of opposing forces made local agreements (“conventions”) to facilitate exchanges of prisoners and protect medical units. Recurrent disputes about particular incidents testified to the persistence of the ideas that there must be standards for governing the conduct of military operations, and that civilized states should wish their armed forces to observe them. So demanding had these ideas become by mid‐nineteenth century that they issued in four epochmaking and trail‐blazing events: the Paris Declaration of 1856, regulating the relations of belligerents and neutrals in maritime war; the
Geneva Conventions of 1864; General Order No. 100 of the U. S. Army of 1864, Instructions for the Government of [Its] Armies in the Field—often known, after its principal author, as “the Lieber code”; and the St. Petersburg Declaration of 1868, a prohibition of an “atrocious” new weapon (explosive bullets).
From those close‐bunched beginnings, the laws of war developed along two main lines. “Geneva law” aimed to protect victims and innocents: the 1929 revision added to the existing conventions (for sick and wounded combatants on land and sea), a third regarding prisoners of war; in 1949, a fourth aimed to protect civilians who fell into enemy hands at the outbreak of hostilities or because of military occupation. The other line, law regarding the conduct of hostilities, of which Francis Lieber's code was for long the most famous and complete national example, became known as “Hague law” after the international standard setting in 1899 (reaffirmed by the Fourth Hague Convention of 1907) of the Hague Regulations Respecting the Laws and Customs of War on Land. Supplemented since 1977 by the First Protocol Additional to the Geneva Conventions (in fact, a convergence of Geneva and Hague law, to which most states by now have acceded), the Hague Regulations have ever been, and still are, fundamental to the laws of land war. Along with the Geneva Conventions, they formed the basis for the war crimes trials after World War II; most of which had to do with the behavior of armed forces in (contested) occupation of alien territories, and with the treatment of prisoners.
Standards for the conduct of war by air and sea have not been so easily reached. In these fields especially, military applications of science and technology have posed problems defying simple solution. New inventions promising military advantage have often at first been denounced as dishonorable or inhumane, but a few have ultimately been added to the list of weapons (e.g.,
chemical and biological weapons) covered by multilateral treaty prohibitions (1925 and 1972, respectively). It remains to be seen how effective will be the 1981 prohibitions or restrictions on the use of certain conventional weapons (mainly
land mines, boobytraps, and incendiary weapons). Efforts were made between 1919 and 1939 to restrict submarine and aerial warfare, but they proved useless during World War II.
Submarines were so vulnerable on the surface that, having to stay submerged, they could not observe the classic distinction between civilian and military; together with mines, they revolutionized war at sea by making possible
blockades more total than ever before. Bombers dared not fly so low or slow that they could guarantee to hit only military objectives; at the same time, the passions of prolonged total war tended to encourage the indiscriminate and terroristic
bombing of civilians. Both sides having waged air and sea war in these extreme and disproportionate ways, they figured hardly at all in the Nuremberg and Tokyo International Military Tribunals and the many nationally run war crimes trials. Not until 1977 were these specific problems addressed. Among the more valuable achievements of the First Additional Protocol is civilian‐protecting definition of military objectives, and, associated with it, rules of proportionality aimed at reducing to the realistic minimum the incidental risks to nonmilitary persons and places.
The laws of war are incapable of perfect observance. Beyond the fact that law like all other elements of war is subject to the erosions of confusion, error, and chance, observance is likely to be highest when states wish a war to remain limited, when neutrals are critically watchful, and when well‐disciplined armed forces fight one another in a relatively civilian‐free environment. The “desert war” in North Africa (1940–43), and the brief Falklands War in the South Atlantic between Britain and Argentina (1982) are exceptional. Circumstances are rarely so favorable. Wars between states are more likely to be all‐out than limited; nor are they often simply between states. The laws of war make some room for “noninternational armed conflict,” but nonstate parties may not wish or be able to conduct hostilities in a style consistent with the law, while states combating them may not like to regard them as if they were lawful belligerents. Civilians tend to be difficult to distinguish from combatants in
guerrilla warfare, or revolutionary and people's wars; in such situations, all parties are tempted to turn to terror. And through it all runs the problem that has forever dogged the laws of war, and whose handling reveals the quality of the culture and the politics of which the warrior is the armed representative: how to distinguish what may be militarily necessary from what is merely convenient, and how to judge when enough violence is enough. Important to all, the laws of war are not a matter of concern solely to the military.
[See also
Geneva Protocol on Chemical Warfare;
Hague Peace Conferences: Just War Theory;
War: Nature of War;
War Crimes.]
Bibliography
Oppenheim's International Law, Vol. 2: Disputes, War and Neutrality, 1905; 7th ed., ed. Hersch Lauterpacht, 1952.
Daniel O'Connell , The Influence of Law on Sea Power, 1975.
David Forsythe , Humanitarian Politics: The International Committee of the Red Cross, 1977.
Philip R. Piccigallo , The Japanese on Trial. Allied War Crimes Operations in the East, 1945–1951, 1979.
Adam Roberts and Richard Guelff, eds., Documents on the Laws of War, 1982; 2nd ed. 1989.
W. Hays Parks , Air Law and the Law of War, Air Force Law Review, vol. 32, no. 1 (1990), pp. 1–225.
Telford Taylor , The Anatomy of the Nuremberg Trials, 1993.
Geoffrey Best , War and Law Since 1945, 1994.
Michael Howard, George J. Andreopoulos, and Mark R. Shulman, eds., The Laws of War: Constraints on Warfare in the Western World, 1994.
Geoffrey Best
