Jessica Di Salvatore*
Obstacle to Peace? Ethnic Geography and Effectiveness of PeacekeepingBritish // Journal of Political Science (2020), 50, 1089–1109

Department of Politics and International Studies, University of Warwick
*Corresponding author. E-mail: jessica.di-salvatore@warwick.ac.uk

Abstract
Under what conditions does peacekeeping reduce one-sided violence in civil wars? This article argues that
local sources of violence, particularly ethnic geography, affect peacekeeping effectiveness. Existing studies
focus on the features of individual missions, yet curbing one-sided violence also depends on peacekeepers’
capacity to reduce the opportunities and incentives for violence. Moving from the idea that territorial
control is a function of ethnic polarization, the article posits that peacekeepers are less effective against
one-sided violence where power asymmetries are large (low polarization) because they (1) create
incentives for escalation against civilians and (2) are less effective at separating/monitoring combatants.
The UN mission in Sierra Leone from 1997 to 2001 is examined to show that UN troops reduce one-sided
violence, but their effectiveness decreases as power asymmetries grow.
Keywords peacekeeping; one-sided violence; ethnic polarization; disaggregated
Do local ethnic configurations affect peacekeepers’ ability to protect civilians? If so, under
what conditions are peacekeepers more effective at saving civilian lives? Existing studies
show that variations in the distribution of ethnic groups shape the dynamics of civil conflict

This article bridges theories on the role of ethnicity and territorial control for the production
of violence in civil war with the literature on peacekeeping effectiveness. Both strands of literature
focus on factors that are usually studied separately but that clearly interact and produce joint
effects on the ground. Peacekeepers are successful at containing violence against civilians;
however, they may also inadvertently create incentives for escalation by signalling insufficient
commitment and changing the balance of power between fighting parties. This signalling
argument finds empirical support when commitment is measured in terms of mission size; larger
and nationally heterogeneous missions have been found to be more effective at protecting
civilians (Bove and Ruggeri 2015; Hultman, Kathman and Shannon 2013). However, it is unclear
how peacekeeping itself changes the balance of power and, in turn, shapes armed groups’
preferences of one type of violence over another. My argument is that the capacity of
© Cambridge University Press 2018.
; First published online 8 October 2018)
British Journal of Political Science (2020), 50, 1089–1109
peacekeepers to reduce violence against civilians is conditional on the local balance of power and
territorial control held by warring parties. Curbing violence in some locations may be more
difficult than in others, and increasing the number of blue helmets on the ground does
not automatically reduce violence. To put it differently, certain features of the conflict can
interact with peace missions and affect their success or failure. Hence, in order to outline the
mechanisms driving some interventions to succeed, the domestic environment has to be explicitly
considered in the theoretical framework as the locus where local sources of hostility and
the local capacity interact to impact UN peace strategies (Doyle and Sambanis 2000; Lyon 2005).
If the objective of peacekeeping is to increase the cost of violence, its effect is necessarily
conditional on what incentivizes violence among combatants (Regan 2002a; Regan 2002b). Since
the dynamics of violence are related to territorial control and the ethno-demographic composition
of locations, ethnic configurations are expected to influence the success and failure of peace
operations.