Book Reviews

What is a Civil War?

By Andrew Kent
Tuesday, March 28, 2017, 8:30 AM

PDF version

A review of David Armitage, Civil Wars: A History in Ideas (Alfred A. Knopf 2017).


John Keegan, the preeminent military historian of our age, writes that warfare between human communities—group on group aggression involving killing or maiming opponents—“is almost as old as man himself.” For Keegan, warfare is not usually a rational continuation of policy by other means, as Clausewitz taught, but instead has more often been driven by culture, emotion, and atavistic aggression. War “reaches into the most secret places of the human heart, places where self dissolves rational purpose, where pride reigns, where emotion is paramount, where instinct is king.”

As a result, as Keegan documents, warfare is both ancient and also, quite often, appalling brutal. It has frequently involved, for instance, refusing to make distinctions between combatants and noncombatants, and glorying in rape, pillage, torture, and even cannibalism. The biological roots of warfare may be quite deep. A primitive kind of warfare may exist among chimpanzees. And even what we see in the mirror every day—our faces, determined by the shape and structure of the human skull—evolved in part to protect the eyes and brain against endemic violence from other primates and then from other humans.

David Armitage, the Lloyd C. Blankfein Professor of History at Harvard University, has written a fascinating book about one kind of warfare, a kind particularly prominent in the current era: civil war. One might think that civil war has always existed—that the lessons of Keegan and the primatologists, anthropologists, and archaeologists is that primitive group aggression would often have occurred within human social groups as well as between groups. But this was not “civil war,” Armitage tells us. His book is rooted in a post-Clausewitzian, rationalist frame, in which humans have developed and debated complex ideas and terminology to describe and justify what exactly it is they are doing when they make war. He calls his work a “history of arguments about civil war,” a “history in ideas.”  And the idea of civil war originated at a specific historical time and place, once certain necessary intellectual and political preconditions were met.

“Civil war was not a fact of nature,” Armitage writes, but “an artifact of culture,” the invention of which can be “dated quite precisely to the first century B.C.E” in the Roman world. The ancient Greeks certainly knew war, and they knew war against other Greeks. But the Romans thought the kind of armed strife they were experiencing in the first century B.C.E. was different. For Romans, war had traditionally been “an armed conflict, for a just cause and fought against an external enemy.” What then, to call armed conflicts among Roman citizens, members of the same political unit with coequal status to each other? The Latin word for citizen—civis—was what named civil war. Rome had fought against Phoenecians (Poeni) in the Punic Wars, against allies (socii) in the Italian peninsula in the Social Wars, and against slaves (servii) in the Servile Wars. The designation of war by citizens against citizens as bellum civile thus followed traditional naming conventions.

Civil war was “novel and unsettling” for this “city-dwelling civilization” which had invented a concept of citizenship that “was a crucial determinant of status, obligations, and rights.” Romans worried that their civilization was “prone to civil war, even cursed by it.” The city—civitas—was conceptually important to the Romans in a way we may find hard to understand. It was supposed to be “a zone of cooperation and peace, where humans could cultivate their humanity under the rule of law.” The Roman jus civile (civil law), the law for people of the same city, political community, and citizenship, was dramatically different than “the law of peoples” (jus gentium), the forerunner of today’s international law, which governed relations with foreigners. As Armitage points out, both linguistically and conceptually civitas and civile are the roots of our words civility and civilization. So when barbarism and violence wracked the city in the form of civil war, and the legal and political community became lawless because war displaced law, it was a terrifying inversion, threatening the destruction of the civilization Romans had built and prized.

Having invented the concept of the bellum civile, Romans inaugurated the pattern that would recur right up to the present: they argued over the scope of the term and which conflicts were properly classified as such, and they tried to diagnose the causes of this most terrible, intimate type of warfare.

One of Armitage’s core points is that “history shows that civil war has had no stable identity or agreed definition.” Thus “[e]stablished governments will always view civil wars as rebellions or illegal uprisings against legitimate authority.” Julius Caesar, when he violated the jus civile by crossing the Rubicon River in arms with his legions, did not concede that this was an act of civil war, but rather styled it a defense of himself and Rome’s liberties against internal enemies.

Motivated reasoning and definitional jousting also marked the intellectual disputes about the causes of Rome’s recurring civil wars. Some located the cause deep in human nature and in Rome’s own DNA: the killing of Remus by his twin brother Romulus during a dispute over which hill their city should be founded on. Others saw moral rot and corruption, deriving from Rome’s wealth, victories, and luxuries, as the cause. A lust for more conquest and more glory drove Romans to contend with each other. Still other Roman historians blamed the Gracchus brothers, with their pro-plebian reform program, for dividing the city into classes, and the violent reaction to the Gracchus reforms for turning that new factionalism into civil strife.

Different lessons were drawn from these differing analyses of causes. Supporters of Augustus Caesar and later emperors argued that only absolute rule could cure Rome of its vicious cycle of civil war. Christians argued that only the spread of their religion throughout the empire could bring internal peace.

Armitage then turns from Rome to the early modern period, starting in the seventeenth century. After the dark ages ended and classical learning spread through the West once again, “Roman accounts of civil war were central to the classical tradition handed down through educational institutions in Europe and the Americas, equipping later generations with a vocabulary and a set of narratives they could apply to their own troubles.” Cicero, Caesar, Lucan, Sallust, Florus, Tacitus, Augustine, and other writers on Roman civil wars educated the West for centuries, and shaped perceptions of the English civil wars, the revolts against Spanish domination in the Low Countries and the Americas and, later, the epoch-shaping revolutions in North America and France. Key intellectual figures such as Hobbes, Locke, Rousseau, Milton, Shakespeare, and Grotius were deeply influenced by the literature of Roman civil wars. Republican thinkers like Algernon Sidney and Thomas Paine drew on Roman sources and theories to argue that monarchy was a primary cause of civil war. Before “democratic peace” was a theory of international relations, it was a theory about internal strife.

Lawfare readers may be most interested in these topics as they intersect with law: questions about how international law and domestic law define and limit civil war and other forms of intrastate armed conflict. Swiss diplomat Emer de Vattel, writing in the mid-eighteenth century, was among the first and most influential to directly address an issue of overriding importance then and now: should sovereigns treat rebellious subjects according to the international laws of war, or should they be treated as criminals under domestic law? As with the concept of civil war generally, there has been no consensus on the definitions and rules governing this key subtopic.

The consequences of the choice of terminology and legal regimes are vast. Take the example of the U.S. Civil War, which Armitage discusses at some length. The Confederates claimed to have become an independent state—this was no civil war to them, but an international war. They thus claimed to be lawful belligerents, who had combatant immunity when they used force consistently with the international laws of war and could seize Union shipping under the international law of prize.

But of course Lincoln and his government rejected the validity of secession: “in contemplation of universal law and of the Constitution the Union of these States is perpetual.” As rebellious citizens of the United States, Confederates could be prosecuted for crimes when they used violence against men and property. But if Confederate soldiers, sailors, and privateers were to be criminally charged and hung as traitors, murderers, and pirates, the Union could expect retaliation in kind. The conflict would quickly devolve into savagery. Thus the U.S. government conceded that as an act of grace it would treat Confederates in arms as legitimate belligerents, for the sake of preserving some humanity and civilization in the conflict, but without conceding that the Confederacy was a lawful government and without permanently renouncing the right to treat Confederates as traitors under domestic law. This “dual theory” of the war prevented tit-for-tat mass slaughter of prisoners and, by helping smooth relations with Europeans powers, fended off outside interference that would have benefitted the Confederacy.  

Armitage is somewhat less interested in this strategic, creative, and successful use of law by the Union government than he is in how the U.S. Civil War fits into the never-ending conceptual battle over the meaning of the term “civil war,” and how it may be distinguished from riots, coups, insurrections, rebellions, and other forms of internal strife. Armitage, for instance, shows how the famous Lieber Code struggled to precisely define “civil war” in a way that would encompass the Union vs. Confederacy struggle, and how Lincoln and others on the Union side considered the conflict more of a “rebellion” than a true civil war.

The book ends where it begins—in modern times. “Civil war has gradually become the most widespread, the most destructive, and the most characteristic form of organized human violence.” Since 1989, the world has averaged twenty intrastate wars at any given time. Intrastate wars last about four times as long as interstate wars, and are much more likely to recur. Efforts to bring some civilization to intrastate conflict have been only mildly successful. Later additions to the Geneva Conventions of 1949 have applied some basic ground rules in “armed conflicts not of an international character occurring in the territory of one of the High Contracting Parties." But debate over which kinds of armed strife are covered continues unabated, except that today lawyers and policymakers throw around new terms like “NIAC” and “IAC.”

The lawyer in me would have liked to hear even more from Armitage about the legal and practical consequences of adopting different terminology to describe kinds of internal conflict, and more about which states and interest groups over the years have pushed for one versus another definition of civil war. This is not a criticism, as such. Armitage does address those topics but, as is his right, his primary focus is slightly different: on the intellectual history of the term. And he succeeds fabulously at his chosen task. This deeply learned and jauntily written book was a joy to read.