To what extent can international peacekeeping promote micro-foundations for positive peace after violence? Drawing on macro-level peacekeeping theory, the authors' approach uses novel experimental methods to illustrate how monitoring and enforcement by a neutral third party could conceivably enhance prosocial behavior between rival groups in a tense, postconflict peacekeeping environment.

"When the conflict in Ukraine began in early 2014, a disturbing number of armed groups—from looting gangs to militias with ties to European white supremacy movements—sprang up from the chaos. Although the role and origin of those pro-Ukrainian militias has been hotly debated, one thing is clear: several years after the start of the conflict, the Ukrainian government has managed to stifle the independent armed groups fighting on its side. Its success offers lessons for other countries attempting to demobilize populations after a war."

To what extent can prosocial norms (re-)emerge among rival groups following intense intergroup conflict? One school of thought posits that violence can strengthen intragroup bonding norms, entrenching parochialism and sustaining in-group biases. However, recent studies suggest that intergroup bridging norms can also improve once conflict ends. The authors' research offers insights into how prosocial bridging vs. parochial bonding norms evolve after violence.

An emerging literature points to the heterogeneous effects of violence on social norms and preferences in conflict-ridden societies. This article considers how responses to violence could be affected by in-group/out-group divisions. The research uses lab-in-the-field experiments to gauge norms for pro-social behavior in the aftermath of ethnic violence in post-war Kosovo. The study finds that one set of treatments (ethnicity) captures a negative legacy of violence on parochialism, while another (local/non-local) shows stronger evidence of pro-sociality and norm recovery.

"...ISIL also wanted to increase the flow of dedicated foreign fighters. For that, they needed to increase the grievances of Western Muslims who could potentially become fighters. France and Belgium were chosen for an attack because those are countries with large Muslim populations, some of whom had already been attracted to ISIL. The attack could increase anti-Muslim sentiment and, as a result, the grievance of Western Muslims, which could increase the number of potential dedicated foreign recruits."

"ISIS has recently suffered massive losses of territory, income, and people. ISIS has lost 25 percent of its territory since the United States began its bombing campaign. The successful Kurdish recapture of Sinjar effectively divided ISIS territory in half and severed its access to the highway that was its main supply route. Based on data we have gathered on the ground, within ISIS territory, in 2014, ISIS was receiving up to 3,000 new recruits and volunteers per day, more than it could process at its own recruiting stations. Just before the Paris bombings, that number had decreased to 50–60 per day, not enough to offset the massive casualties sustained in Sinjar and elsewhere."