research

The legitimacy of armed forces in the eyes of civilians is increasingly recognized as crucial not only for battlefield effectiveness but also for conflict resolution and peace-building. However, the micro-determinants of “military legitimacy” are poorly understood. We argue that perceptions of military legitimacy are shaped by two key dimensions of warfare: just cause and just conduct. Leveraging naturally occurring variation during one of the most deadly urban battles in recent history—the multi-national campaign to defeat the Islamic State in Mosul, Iraq—we evaluate our theory with a mixed-methods design combining original survey data, satellite imagery, and interviews. Civilians living in neighborhoods where armed forces were less careful to protect civilians view those forces as less legitimate than civilians elsewhere. Surprisingly, these results persist after conditioning on personal experiences with harm, suggesting that perceptions are influenced not only by victimization—consistent with previous studies—but also by beliefs about the morality of armed forces’ conduct and the cause for which they are fighting.

The world faces a forcible displacement crisis. Tens of millions of individuals have been forced across international boundaries worldwide. Therefore, the causes and consequences of refugee flows are the subjects of significant social science inquiry. Unfortunately, the historical lack of reliable data on actual refugee flows, country-specific data reporting timelines, and more general pre-2000 data quality issues have significantly limited empirical inferences on these topics. We replicate twenty-eight articles on these topics using data newly released after a multi-year collaboration with the United Nations on annual dyadic flows. We observe major inconsistencies between the newly released flow numbers and the stock-based flow estimates upon which decades of research are based; we also find widespread inappropriate treatment of missing historical values. When we replicate the existing literature using the newly introduced flow data, correcting the treatment of missing historical values, and temporally extending/restricting the study periods, we produce significantly different results.

How does refugee return shape conflict in migrants' destination communities? We argue that conditions inducing repatriation bear critically on the consequences of return. When refugees return because of worsening conditions in host countries, they are often marginalized and destitute. In this setting, mass return risks amplifying conflict in returnee-receiving communities. We test this theory leveraging the Trump administration's sudden reimposition of sanctions on Iran in 2018. These "Maximum Pressure" sanctions decimated the Iranian economy and spurred mass return of Afghan refugees from Iran. Exploiting historical returnee settlement patterns and the plausibly exogenous timing of the sanctions, we estimate the causal effect of large-scale refugee repatriation on violence. We find that the returnee influx increased insurgent violence in returnees' destination communities. We find suggestive evidence for an opportunity cost mechanism. Sanctions-induced currency depreciation reduced household incomes in returnee-receiving areas, lowering reservation wages and driving up insurgent recruitment. We also find evidence that Iran retaliated against the sanctions by escalating support for Afghan insurgent factions. While insurgent violence increased in repatriation communities, there was no effect on communal conflict.

After the resolution of a civil conflict, how does the return of the internally displaced population (IDPs) impact social cohesion? Little attention has been paid to the consequences of IDP return, despite extensive research on the causes and effects of displacement. I investigate this question in Iraq after the defeat of the Islamic State. Coercive and unexpected camp closures by the Iraqi federal government starting in July 2019 forced hundreds of thousands of internal migrants to return. The exogenous timing of the closure campaign provides a unique setting to estimate a plausibly causal effect of return. Leveraging village-level displacement data, community assessments, respondent-level surveys, and qualitative fieldwork, I find that the closure-induced returns frayed social cohesion. My theory provides a critical mechanism underpinning this relationship: return creates communal tensions by inducing feelings of fear and suspicion. These findings hold significant policy implications, as the approach of post-conflict governments to address internal migration profoundly influences the social legacy of civil conflicts.