William G. Nomikos

"With careful fieldwork, experiments, cross-national analyses, and in-depth case studies, Nomikos provides compelling evidence that UN peacekeepers are uniquely capable of reducing communal violence. Readers will gain a novel perspective on the role of peacekeeping."

Kyle Beardsley, Duke University

"Through an artful combination of research methods, Nomikos underscores the importance of peacekeeper impartiality. Citizen perceptions of peacekeepers, we learn, make an enormous difference in the effectiveness of post-conflict recovery. Both scientific and optimistic, this book is a model for the next generation of peacekeeping research."

Susan D. Hyde, University of California, Berkeley

"How do UN peacekeepers keep the peace? Using interviews with local leaders and peacekeepers, behavioral games, surveys, and georeferenced data on troops, Nomikos finds that when peacekeepers are viewed as impartial, they de-escalate local conflicts. A must-read for anyone interested in peacekeeping."

Lisa Morjé Howard, Georgetown University

"Although UN peacekeeping is often viewed skeptically, Nomikos demonstrates that it can have positive effects in mitigating conflicts when peacekeepers are perceived to be impartial. A thoroughly researched, multi-method study that explains when, how, and why peacekeeping matters with important lessons for the conduct of future missions."

David A. Lake, University of California, San Diego

My first published book, Local Peace, International Builders: How the UN Builds Peace from the Bottom Up, examines the conditions under which international actors successfully bring order, peace, and stability to fragile settings.

View my book online through Cambridge University Press.

  • Brief Summary

    Communal disputes over local issues such as land use, cattle herding, and access to scarce resources are a leading cause of conflict around the world. Over the coming decades, climate change, forced migration, and violent extremism will exacerbate such disputes in places that are ill equipped to handle them. UN peacekeeping operations are the international community’s primary tool for managing conflict. Despite abundant evidence that peacekeepers limit large-scale fighting between armed groups, we know little about their ability to prevent more localized forms of violence. Local Peace, International Builders explains the conditions under which UN peacekeeping operations promote peaceful interactions between civilian communities in fragile settings. Its central theoretical insight is that civilian perceptions of peacekeepers’ impartiality shape their ability to manage local disputes. To support this claim, I collected georeferenced data on the deployment of more than 100,000 peacekeepers to localities across Africa from 1999–2019. I also gathered data from extensive field research in Mali, a West African country with widespread violence managed by peacekeepers: nearly 50interviews with local political, religious, and traditional leaders, behavioral games with more than 500 Malians from 14 ethnicities, and surveys of 1,400 civilians. The book highlights a critical pathway through which UN peacekeeping may successfully maintain order in the international system. The findings have clear implications for how we think about international interventions—and how they can be better designed in the future to prevent violence in conflict and post-conflict settings.

  • 1. Introduction

    This introductory chapter explains the book’s motivating puzzles and outlines its theoretical and empirical strategies. The book focuses on local-level peacekeeping operations designed explicitly to prevent communal violence. It argues that deploying UN peacekeepers to fragile settings fundamentally changes the structural incentives facing communities in conflict. Scholars typically pinpoint the UN’s success at the negotiating table: peacekeepers help armed group leaders make lasting agreements that stabilize conflict settings from the top down. Yet such negotiations seem unable to prevent communal violence in places as diverse as South Sudan in East Africa, Mali in West Africa, and the Democratic Republic of the Congo in Central Africa. This book shifts the analytical lens to the local level to investigate the conditions under which peacekeepers successfully build peace from the bottom up. The book’s main argument is that UN peacekeepers succeed when local populations perceive them to be relatively impartial enforcers who are unconnected to the country of deployment, the conflict, and the parties to the dispute. Impartial peacekeepers convince all parties that they will punish those who escalate communal disputes regardless of their identity, which increases communities’ willingness to cooperate without the fear of violence.

  • 2. The Evolution of Local-Level UN Peacekeeping

    This chapter explains how UN peacekeeping operations (PKOs) have changed over time, paying particular attention to how UN PKO mandates have evolved to address communal disputes. It begins with a general overview of UN PKOs over time. The chapter then briefly reviews the academic research on international interventions, which offers robust evidence that peacekeepers bolster peace and stability after conflict. However, this scholarship has not sufficiently examined whether (or how) UN PKOs limit communal violence. Communal disputes are a critical source of instability, violence, and disorder around the world, particularly in sub-Saharan Africa. Conflict from such disputes has killed nearly 250,000 people in the region since the turn of the century, more than violence from governments or rebel groups. And the problem is getting worse. Given that climate change, global migration patterns, and the growth of violent extremism will likely exacerbate communal disputes in the coming years, it is vital to understand how UN peacekeepers can help resolve them. The chapter discusses what distinguishes communal violence from other forms of intrastate violence before concluding with a summary of local-level UN PKOs designed to address communal disputes.

  • 3. A Micro-Level Theory of UN Peacekeeping

    Chapter 3 presents localized peace enforcement theory. It first discusses the challenges facing individuals involved in a communal dispute. Reflecting on these obstacles to peaceful dispute resolution, the chapter outlines a formal micro-level theory of dispute escalation between two individuals from different social groups who live in the same community. It explains how international intervention shapes escalation dynamics. The chapter then shifts the focus to local perceptions of intervener impartiality, which the theory posits are a key determinant of whether a UN intervention succeeds in preventing the onset of violence. The identifies the importance of multilateralism, diversity, and the nonuse of force as critical factors shaping local perceptions and, as a result, UN peacekeeping effectiveness. Critically, the theory does not suggest that UN peacekeepers will always succeed, or that all kinds of UN peacekeepers will succeed. Indeed, perceptions of UN peacekeepers vary depending on the troop-contributing country and the identity of the civilians involved in the dispute. The chapter closes with a discussion of the most important hypotheses derived from the theory.

  • 4. Research Design

    This chapter describes the data collection strategy and multimethod research design employed to test the theory in the subsequent chapters of the book. The structure of the empirical analysis mirrors the book’s primary argument: to show how peacekeeping works from the bottom up, from the individual to the community to the country. Given that UN peacekeepers deploy to the most violent areas, the design needed to account for selection bias as well as other confounding variables in order to make causal inference possible. Using data from individual- and subnational/community-level data from Mali as well as cross-national data from the universe of multidimensional PKOs deployed in Africa, the book employs a three-part strategy to test the hypotheses in the next few chapters. First, the book considers the micro-level behavioral implications of the theory using a lab-in-the-field experiment and a survey experiment, both implemented in Mali. Second, it test whether UN peacekeepers’ ability to increase individual willingness to cooperate aggregates upward to prevent communal violence in Mali. Third, the book considers whether these findings extend to other countries.

  • 5. Introduction to Ethnic Conflict and International Intervention in Mali

    This chapter begins the second part of the book, which tests the main empirical implications of localized peace enforcement theory using data from Mali, a land-locked country in West Africa. Though Mali experienced three coups, a separatist civil war, and an Islamist extremist insurgency from 2012 to 2024, no source of conflict has been more fatal or detrimental to Malian society than communal violence. The chapter starts by providing a very brief history of identity-based conflict in the country. It also places Mali within a broader historical context and demonstrates that its experience of interethnic tensions is representative of countries with colonial legacies. The chapter then draws on detailed interviews with forty-eight local leaders to describe what communal violence and peacekeeping look like in Mali from the residents’ perspective. Given the theoretical importance domestic perceptions of peacekeepers, these interviews offer crucial insights into the plausibility of localized peace enforcement theory. There are distinct advantages of studying the Malian case, which the chapter describes in a brief overview of international interventions by the UN and France from 2012 to 2024.

  • 6. Individual Peace

    This chapter tests observable implications of localized peace enforcement theory at the individual level using two experiments conducted in Mali. First, the chapter presents the results of a study designed to measure willingness to cooperate using a trust game where participants send money to an anonymous partner from a different ethnic group. A randomly assigned group of participants is told that two patrolling officers (from either the UN or France) will punish any low partner contributions with a fine. While the UN treatment increased participants’ willingness to cooperate, the France treatment had no effect. Follow-up interviews confirmed the importance of perceptions of the UN’s impartiality. Second, the chapter outlines the results of a survey that presents respondents with a vignette describing a communal dispute. Respondents were then randomly assigned to a control, UN, or French treatment group. Assignment to the UN treatment group – but not the French treatment group – reduced the likelihood that respondents said a communal dispute would escalate. To probe the plausibility of localized peace enforcement theory specifically, the chapter concludes with an analysis of specific questions about individuals’ perceptions of peacekeepers from the survey.

  • 7. Communal Peace

    This chapter applies localized peace enforcement theory to a subnational analysis of patterns of dispute escalation in Mali. In order to investigate whether the previous chapters’ experimental findings generalize to real-world operations, the chapter presents the results of two analyses of UN peacekeeping efforts to prevent the onset of communal violence in the central Malian region of Mopti. The first study leverages a geographic regression discontinuity design to compare dispute escalation on either side of the Burkina Faso–Mali border. The border splits similar areas into those “treated” with UN peacekeeping patrols (on the Mali side) and “control” areas without peacekeeping (on the Burkina Faso side). The findings indicate that peacekeeping reduces the likelihood of communal violence. The second study delves deeper into the data with an analysis of UN peacekeepers from different countries deployed to the same regions of Mali and uncovers further evidence in line with the predictions of the theory. Rather than comparing UN peacekeeping in countries with against those without a peacekeeping operation, the study compares UN peacekeepers from different contributing countries – Togo and Senegal – deployed to the same area.

  • 8. International Peace

    This chapter examines local-level peacekeeping operations in a cross-national context. The analysis draws on a dataset of nearly 400,000 georeferenced troop deployments in sub-Saharan Africa from 1999 to 2019. Consistent with the theory’s predictions, it demonstrates that increases in the number of peacekeeping troops deployed to local communities are strongly positively associated with decreases in the onset of communal violence. Since cross-national data of this sort cannot directly measure local perceptions of peacekeepers cross-nationally, the study tallies the number of peacekeepers from former colonial powers and neighboring countries deployed to each area as a proxy for perceptions of bias. The patterns further vary in ways that support the logic of localized peace enforcement theory. Specifically, the evidence shows that there is no relationship between the deployment of these two types of peacekeepers and levels of communal violence. The analyses presented in the chapter also detect a strong negative association between all other types of peacekeepers, likely to be perceived as impartial, and the onset of communal violence.

  • 9. Conclusion

    Chapter 9 concludes the book by highlighting implications that are relevant for academic researchers as well as policymakers. The book’s findings suggest at least three areas for future research. First, a more comprehensive analysis of the sources of perceptions of bias in conflict settings would productively inform scholarship and practice. Second, future work should investigate the conditions under which communal peace aggregates up to the national level. Third, scholars should examine whether governments and their partners succeed in leveraging gains from localized peace enforcement into states with robust institutions. The book also has two important implications for the practice of peacekeeping. First, given the importance of perceptions, policymakers must ensure that peacekeepers remain impartial. International actors perceived by local populations as relatively impartial are much more effective at promoting intergroup cooperation and facilitating the peaceful resolution of communal disputes. Second, given that communal peace in the analysis relies so heavily on the presence of UN peacekeepers, the international community must consider how to design peaceful transitions out of PKOs.

CV