Book Review: The Calculus of Violence by Aaron Sheehan-Dean

Sheehan-Dean, The Calculus of Violence: How Americans Fought the Civil War


For decades, historians have debated whether the American Civil War was the first modern, total war, foreshadowing the World Wars of the 20th Century, or whether it was more akin to the limited wars of the 18th Century. In his thorough study, The Calculus of Violence, Professor Sheehan-Dean comes down on the limited-war side of the spectrum, while also conceding that for some groups the war was close to total. The violence of the Civil War, he concludes, did not fit neatly into any category, but rather offered a “tangle of lessons.”

That both the Union and the Confederacy held themselves out to be modern, civilized nation states was, the author believes, an important restraint on their use of violence. Regular armies on both sides fought according to the accepted laws and customs of war. Despite its refusal to recognize the Confederacy as a government, the Union ended up applying the international laws of war to its adversary, and even issued a concise codification of those laws for the guidance of its troops.

The author identifies the institution of formal surrender as a prime vehicle for ensuring restraint. Soldiers subject to a surrender agreement could be assured that they would be regarded as legitimate combatants and treated as prisoners of war rather than criminals.

These restraints began to erode in the final years of the war. The North intensified its destruction of the South’s economic infrastructure, most notably in the Shenandoah Valley of Virginia in 1864 and in General Sherman’s campaigns in Georgia and the Carolinas in 1864-65. While Southern civilians were not directly attacked, the destruction of their livelihood produced substantial suffering, particularly for the women. In response, the Confederacy launched terror attacks on Northern civilians, including an effort to burn Manhattan in New York, and a raid on Albans, Vermont.

The author attributes this loosening of standards to frustration, on both sides, at the failure of conventional military operations to produce victory, and to the “just war” ideologies embraced by both sides. The United States identified its cause with the future of democracy world-wide. As President Lincoln put it, a Union victory was the “last best hope” on earth for the cause of self-government. The South, in turn, regarded itself as defending a morally superior agrarian way of life against the mercenary, capitalist North. In the final year of the war the speeches of Jefferson Davis emphasized this theme to rally his people to the cause.

The author treats both ideologies as morally equivalent nationalist rhetoric, little more than rationalizations for waging harder war. He does not engage Lincoln’s position as a serious argument. In reality, there was a widespread consensus among European elites that, while democracy might work in a small state like Switzerland or the Netherlands, it was not viable in a large, diverse country. By 1860, republicanism had been tried twice in France and failed both times. To those holding this view, the secession of the Southern states proved that governments relying on elections for political legitimacy were inherently unstable; the losing side would simply secede, destroying the country. Stability in a large nation required hereditary monarchy or aristocracy.

This is what President Lincoln meant when he said that the central idea of secession was “the essence of anarchy.” To prove that self-government was feasible, he believed it was necessary that the majority demonstrate the political will to compel a seceding minority to accept the results of a general election. While it cannot be proven that Confederate victory would have set back the cause of self-government in the 19th Century, Lincoln’s position had a rational basis, unlike Jefferson Davis’ “moonlight and magnolias” view of the Old South.

The author emphasizes that even before the final escalation of violence, the traditional laws of war provided little protection to certain groups. For members of these groups the Civil War could be total war, since their treatment was largely at the discretion of their captors. For the Union, these discretionary groups included enemy guerrillas and the inhabitants of occupied territory. For the Confederacy, they included African American soldiers of the U.S. Army and their white officers, free African Americans in areas invaded by the Confederate army, and refugees fleeing slavery. The arbitrary treatment of these groups was exacerbated by the decentralized character of both the Union and Confederate war efforts. Even in the age of the telegraph, irregular fighting units could be raised and operate with no sanction and little supervision from central authorities. Field commanders were often left to their own discretion in dealing with members of unprotected groups.

Even here, however, the author finds institutions and practices that limited discretion in the treatment of such groups. Threats of retaliation were an important motive for restraint. While the official position of the Confederate government was that African American soldiers were not entitled to prisoner of war status, actual practice of Confederate officers in the field varied widely. Many captured members of the U.S. Colored Troops were treated as prisoners of war, though this often led to the doubtful privilege of being sent to Andersonville. The author attributes this partial restraint to the Lincoln administration’s threat to retaliate against Confederate prisoners for abuse of African American soldiers.

Sheehan-Dean also argues that planned executions of Confederate guerrillas, and execution of civilian hostages in response to guerrilla activities, were often prevented by threats of retaliation. He detects a common pattern that ran as follows: Federal authorities would announce a forthcoming execution; Confederates would protest and announce plans for a retaliatory execution; leading to suspension of both killings and an eventual diplomatic solution often involving an exchange of captives.

In response to guerrilla attacks, the Union army routinely imposed collective punishments on hostile populations to deter them from supporting the insurgents, such as burning all houses within a certain distance from the scene of an attack. While such measures inflicted hardship on civilians, they tended to have little impact on the guerrillas. The author discusses one prominent case, “General Order No. 11,” exiling all civilians from several northern Missouri counties in response to Confederate guerrilla Quantell’s destruction of Lawrence, Kansas. The author notes that President Lincoln believed the order was humane in the long run because it defused the likelihood of a bloody reprisal raid into Missouri by Kansas Unionists. The author does not identify any institutional restraints on collective punishments during the war. As the result of abuses in the 20th century, the 1949 Geneva Convention on Civilians now prohibits all collective punishment of inhabitants of occupied territory.

While the author does not address this subject, readers of Lincoln Lore may be interested in President Lincoln’s own policies in discretionary cases. He did not lay down general guidance for the treatment of guerrillas and enemy civilians, but became involved as individual cases were appealed to him. As might be expected, he was often inclined towards leniency. For example, he suspended a collective fine on Virginia civilians for the destruction of a lighthouse by guerrillas, and intervened to protect the wife of a Confederate soldier whose Arkansas house had been seized by the army. A theme consistently running through Lincoln’s decisions was that punitive actions must be justified by military necessity, and never taken merely for revenge.

The Calculus of Violence is a comprehensive, almost encyclopedic, study of the uses of violence during the Civil War. It will be of interest to both scholars and general readers interested in that war, as well as readers interested in the development of restraints on war.


Reviewed by Burrus M. Carnahan, United States Department of State

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