As documented in Chapter 1, wars within states have become far more numerous than wars between states, especially in recent decades. Over the period 1990–2006, for example, the Uppsala Conflict Data Program/Peace Research Institute, Oslo identified 23 war onsets within states compared to three between states. In this chapter we present theoretical and empirical perspectives on the onset, termination, and consequences of violent intrastate conflicts, particularly civil wars and genocides.
For the purposes of this chapter, we draw on Marshall, Gurr, and Harff (2001, p. 5) and Sambanis (2002, p. 218) to define civil war as violent conflict within a country between a government and one or more internal opposition groups, with sizeable fatalities on each side. Scholars differ over the level of violence that qualifies as a civil war, but for coding purposes a fatality threshold of 1,000 is sometimes used. To distinguish it from a massacre, a civil war must entail sizeable fatalities on both sides. The Correlates of War Project, for example, requires that the stronger side's fatalities be least 5 percent of the weaker side's fatalities to qualify as a civil war (Henderson and Singer 2000, pp. 284–285).
An internal opposition group is generally identified by political, ethnic, religious, or cultural characteristics, and its objective might be to overthrow the government, seize power in a particular region, secede, or obtain major changes in its political, economic, or social status (Marshall, Gurr, and Harff 2001, p. 5).