The American Civil War: Total or Just?

Question

Were there any international rules of war at the time of the American Civil War? When the policy of total war was put into practice, was there any 19th-century type version of the Geneva Conventions in place? What was the United States' official stance on a "just war" or didn't we subscribe to that then?

Answer

Instead of binding international rules or conventions, the major pressure for armies to behave responsibly in wartime in the mid-19th century came from the philosophical and religious beliefs behind the theory of “just war.” Drawing on the writings of St. Augustine and Thomas Aquinas, scholars such as Francisco de Vitoria and Hugo Grotius began to systematize the various aspects of the just war theory in the 16th and 17th centuries. Most Americans encountered the ideas of just war through the writings of Emerich de Vattel, a Swiss-born theorist whose 1758 Law of Nations explained when nations could legitimately resort to armed conflict and how they could behave once engaged. The just war theory (then and now) does not seek to eliminate war but to establish uniform rules that will limit the scope of conflicts, especially the practice of lethal violence and property destruction against innocent non-combatants. In common with European military and political leaders, most Americans on both sides of the Civil War conflict were familiar with the guiding principles, if not the details, of the just war doctrine.

It is important to note that when the phrase “total war” is applied to the U.S. Civil War it has a very different meaning than when it is used to describe 20th-century conflicts. In the latter case, total war indicates the use of air power and strategic bombing to disable an enemy’s infrastructure—roads, power plants, etc.—but also to target whole cities and the civilian populations within them. This form of total war produces indiscriminate use of lethal force, as the millions of non-combatant deaths in both theaters of World War II attest. In the Civil War, by contrast, we can see that both sides selected the targets of lethal violence with fairly high precision. Actors on both sides committed atrocities and sometimes violated the rules of war, but compared to other conflicts of a similar nature civilians suffered relatively little direct physical harm. Although many of the Civil War’s participants conceptualized the conflict as a total war, they did so largely because the war demanded (at least for the South) that all of the nation’s resources be devoted to fighting the war. However, both armies did consume and destroy vital resources, leaving the citizenry to suffer as a result. The policy of logistical devastation practiced by Grant and Sherman late in the war was consistent with just war theory.

In 1863, the U.S. government published General Order No. 100, “Instructions for the Government of the Armies of the United States in the Field.” Written by Francis Lieber, the German-born jurist and political philosopher, this manual was widely distributed and read within both the United and Confederate States. Lieber drew on the principles of just war and the work of men like Vattel and Grotius to craft concrete policies for the army. Critics focused mostly on the loopholes (which were ample) but the code represented the first legal definitions for many of the concepts that had circulated under the mantle of just war theory for centuries. Historians disagree about how much credit or blame should be given to Lieber and the code for the patterns of violence that emerged in the conflict in 1864–1865. Most would agree that Lieber’s code influenced the drafting of the first Geneva Convention in 1864 and helped to bring greater rigor and uniformity to the protection of non-combatants in wartime.