deployments can be politically and materially costly,
but the benefit of these actions not only manifests in a
reduction of deaths on the battlefield, but a lessening
of tensions between combatants in a period when the
risk of war renewal is great.
Additional evidence suggests that peacekeepers
are even better at preventing civilian casualties in civil
wars. Hultman and colleagues also find that peacekeepers have a larger impact in preventing the loss of
civilian lives.29 With no armed UN troops, the average monthly number of civilian casualties is 106. A
smaller increase to 8000 troops drops the average to
less than 2, holding other relevant factors constant.
Police forces are perhaps even more effective. With
no UN policing, the average number of civilian casualties in a civil war is 96 per month. In their model,
with a police force of only 200, the average number of
civilian casualties decreases to only 14. A police force
of 500 reduces casualties to nearly zero.30 Although
mandates for armed troops and police are well-suited
to protect civilians, monitors are less capable and are
actually associated with an increase in civilian deaths.
Perhaps this occurs when perpetrators are not deterred and even spurred on by monitoring missions
to attack civilians before a “stronger” peacekeeping
force arrives.
Although these results are encouraging from a
humanitarian perspective, actual patterns in the deployment of peacekeepers may hinder their ability
to prevent casualties. Jacob Kathman’s data on UN
peacekeeping deployments suggest that most missions involve suboptimal deployments and therefore
might be too small to prevent casualties.31 Recall that
a deployment of 10,000 armed troops can reduce battlefield casualties by 70 percent, but the average de-
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