This article presents new data on the direct and deliberate killings of civilians, called one-sided violence, in intrastate armed conflicts, 1989—2004. These data contribute to the present state of quantitative research on violence against civilians in three important respects: the data provide actual estimates of civilians killed, the data are collected annually and the data are provided for both governments and rebel groups. Using these data, general trends and patterns are presented, showing that the post-Cold War era is characterized by periods of fairly low-scale violence punctuated by occasional sharp increases in violence against civilians. Furthermore, rebels tend to be more violent on the whole, while governments commit relatively little violence except in those few years which see mass killings. The article then examines some factors that have been found to predict genocide and evaluates how they correlate with one-sided violence as conceptualized here. A U-shaped correlation between regime type and one-sided violence is identified: while autocratic governments undertake higher levels of one-sided violence than other regime types, rebels are more violent in democratic countries.

Does United Nations peacekeeping protect civilians in civil war? Civilian protection is a primary purpose of UN peacekeeping, yet there is little systematic evidence for whether peacekeeping prevents civilian deaths. We propose that UN peacekeeping can protect civilians if missions are adequately composed of military troops and police in large numbers. Using unique monthly data on the number and type of UN personnel contributed to peacekeeping operations, along with monthly data on civilian deaths from 1991 to 2008 in armed conflicts in Africa, we find that as the UN commits more military and police forces to a peacekeeping mission, fewer civilians are targeted with violence. The effect is substantial-the analyses show that, on average, deploying several thousand troops and several hundred police dramatically reduces civilian killings. We conclude that although the UN is often criticized for its failures, UN peacekeeping is an effective mechanism of civilian protection.

While United Nations peacekeeping missions were created to keep peace and perform post-conflict activities, since the end of the Cold War peacekeepers are more often deployed to active conflicts. Yet, we know little about their ability to manage ongoing violence. This article provides the first broad empirical examination of UN peacekeeping effectiveness in reducing battlefield violence in civil wars. We analyze how the number of UN peacekeeping personnel deployed influences the amount of battlefield deaths in all civil wars in Africa from 1992 to 2011. The analyses show that increasing numbers of armed military troops are associated with reduced battlefield deaths, while police and observers are not. Considering that the UN is often criticized for ineffectiveness, these results have important implications: if appropriately composed, UN peacekeeping missions reduce violent conflict.