A civil war is a war in which the competing parties are segments of the same country or empire. Civil war is usually a high intensity stage in an unresolved political struggle for national control of state power. As in any war, the conflict may be over other matters such as religion, ethnicity, or distribution of wealth. Some civil wars are also categorized as revolutions when major societal restructuring is a possible outcome of the conflict.
Pre-modern civil wars
Conflicts of succession between the monarch or ruler and a pretender occurred in almost all pre-modern systems of government. These conflicts for control of a state could take international form, and often even in civil disputes the factions would have the support of outside powers. Most historians believe that these conflicts were generally rooted in squabbles between the aristocracy and ruler, or a product of economic or social change and upheaval.
Early states of any great size had difficulty controlling their regions and relatively decentralized rule was the norm. This left local administrators, landowners, and other nobles a great deal of sovereignty. In most cases this extended to having control of their own armed forces. If so motivated these vassals could decide to overthrow their sovereign and rebel if successful they could either separate to form their own state or unseat the ruler and usurp control over the entire polity.
While in the traditional literature the above two types of conflict were the most written about, modern historians are increasingly looking at peasant revolts. Revolts by the peasantry, and other indentured labourers such as slaves, have been common to almost all societies dependent on such forms of labour. These would break out in response to increased obligations or cruelty by a ruler, famine or economic failure in the state, among other causes. While there are many hundreds of such revolts recorded through history hardly any were successful and they were almost always crushed by the forces of the government and aristocracy.
Of course it is impossible to subdivide civil wars into neat categories. Many conflicts were a mix of these groups. Peasant revolts would often catalyze around a pretender. Disputes over succession would almost always involve the revolt of vassals. While these are labels for types of early civil wars, they are not explanations of their cause.
What is general agreed upon is that factors such as nationalism, religion, and ideology, played little role in pre-modern civil wars. While it is quite common for nationalists to read past revolts, such as those of Scotland against Britain as early stirrings of nationalism, this is a somewhat suspect notion. Religion is more contentious, there are some civil wars that can be seen as fueled by religion in early years, such as the Jewish Revolts against Rome, but these an also be seen as revolts by a servile people against their oppressors or uprisings by local notables in an attempt to gain independence.
Civil wars over religion are unlikely in polytheistic societies where religions tend to be flexible and accommodating enough to prevent intercine violence. Even with the arrival of monotheism in Zoroastrianism and the Abrahamic religions religious revolts were rare. In earlier times a nation's religion was defined the religion of the sovereign and the elite and it was not dogmatically imposed by upon the mass of the population. Thus even in Europe through the Middle Ages the Christianity of the great bulk of the population was limited and still much infused by pagan traditions. With religion so loosely applied it was rare for people to feel like they must rebel against it. The one exception in Medieval Europe was the occasional rise of heresies such as that of the Albigensians. These tended to be the product of peasant revolts rather than themselves motivators of a civil war.
Religion did not begin to play an important role in the causation of civil wars until the religions stressing individual salvation were introduced. The first of these is arguably Islam which saw a rash of uprisings against non-Islamic rulers soon after its appearance. Subsequent Islamic history has been marked by repeated civil conflicts, mostly stemming out of the Shi'ite Sunni divide. In Europe the Protestant Reformation had a similar effect sparking years of both civil and international wars of religion. Civil wars between Catholicism and Protestantism consumed France in the Wars of Religion the Dutch War of Independence and violence between Protestant sects played an important role in the English Civil Wars. Some historians both Marxist and non argue that even in these eras religion was never the root cause of civil war but merely a justification and rationalization for wars that were fought for reasons of economics or power politics.
A revolution is generally seen as a civil war fought over issues of ideology, over how power should be organized and distributed, not merely over which individuals hold it. The classic example of a revolution, and by some arguments the first is the French Revolution, which is seen to have pitted the middle class and urban poor of France against the aristocracy and monarchy. Some argue that revolutions are a modern continuation of the peasant revolts of the past. Unlike peasant revolts, however, revolutions are almost always lead by members of the educated, but disaffected, middle class who then rally the large mass of the population to their cause. Others see ideology as merely replacing religion as a justification and motivation for violence that is fundamentally caused by socioeconomic factors. To be successful revolutions almost always require armed force to be employed, sometimes escalating to a civil war, such as in the Chinese Civil War. In some cases, such as the French and Russian Revolutions and revolutionaries succeed in gaining power through a quick coup or localized uprising, but a civil war results from counterrevolutionary forces organizing to crush the revolution.
One of the most common causes of civil wars, especially in the post-Cold War world has been separatist violence. Nationalism can be seen as similar to both a religion and an ideology as a justification for war rather than a root cause of conflict. All modern states attempt to hold a monopoly on internal military force. For separatist civil wars to break out thus either the national army must fracture along ethnic, religious, or national lines as happened in Yugoslavia. More commonly a modern separatist conflict takes the form of asymmetrical warfare with separatist lightly armed and disorganized, but with the support of the local population such groups can be hard to defeat. This is the route taken by most liberation groups in colonies, as well as forces in areas such as Eritrea and Sri Lanka. Regional differences may be enhanced by differing economies, as in the American Civil War. National minorities are also often religious minorities and wars of religion may link closely into separatist conflicts.
[[Coup d'�tat]]s are by definition quick blows to the top of a government that do not result in the widespread violence of a civil war. On occasion a failed coup, or one that is only half successful, can precipitate a civil war between factions. These wars often quickly try to pull in larger themes of ideology, nationalism, or religion to try to win supporters among the general population for a conflict that in essence is an intraelite competition for power.
Again the forces of religion, ideology, and nationalism can rarely be considered the root cause of a civil war. Almost every nation has minority groups, religious plurality, and ideological divisions, but few plunge into civil war. Sociologists have long searched for what variables trigger civil wars. In the modern world most civil wars occur in nations that are poor, autocratic, and regionally divided. However the United States was one of the wealthiest and most democratic countries in the world at the time of its bloody civil war.
Some models of why civil wars occur stress the importance of change and transition. Thus the American civil war was caused by the growing economic power of the north relative to the south; the Lebanese Civil War by the upsetting of the delicate demographic balance by the increase in the Shi'ite population; the English Civil War by the growing power of the middle class and merchants at the expense of the aristocracy.
Competition for resources and wealth within a society is seen as a frequent cause for civil wars, however economic gain is rarely the justification espoused by the participants. Marxist historians stress economic and class factors arguing that civil wars are caused by imperialist rulers battling each other for greater power, and using tools such as nationalism and religion to delude people into joining them. Revolutions, which many Marxists see peasant revolts as a prelude to, are a completely different phenomena motivated by spontaneous rejection of elite domination and economic oppression by the working class.
Continuation of civil wars
Not only are the causes of civil wars widely studied and debated, but their persistence is also seen as an important issue. Many civil wars have proved especially intractable, dragging on for many decades. Civil wars often become proxy wars for outside powers that fund their partisans and thus encourage further violence.
Conflict rebuilding after a civil war is often difficult. In an international war the two parties merely have to desists from killing each other and can, for the most part, go their own ways. In a civil war not only must violence stop but the factions involved must also learn to coexist with each other. This can often prove difficult, much of the population will have lost friends or loved ones in the war, losses they blame on their opponents. Civil wars also tend to greatly entrench any ethnic, religious, or ideological divisions within a society and restoring unity can be very difficult. United Nations peacekeeping has proved to sometimes be successful in healing such war torn societies.