How do people power movements succeed when modest proportions of the population participate? We propose that the effects of social movements increase as they gain momentum. We approximate a simple law drawn from physics: momentum equals mass times velocity (p=mv). We propose that the momentum of dissent is a product of participation (mass) and the number of protest events in a week (velocity). We test this simple physical proposition against panel data on the potential effects of movement momentum on irregular leader exit in African countries between 1990-2014 using a variety of estimation techniques. Our findings show that social movements potentially compensate for relatively modest popular support by concentrating their activities in time, thereby increasing their disruptive capacity. Crucially, these findings also provide a straightforward way for dissidents to easily quantify their coercive potential by assessing their participation rates and increased concentration of their activities in time.

When and why do groups participating in mass dissent choose to initiate terrorist campaigns? I argue that groups involved in civil wars and mass civil resistance might face similar organizational pressures, which encourage the initiation of terrorism due to higher tactical effectiveness. Internal organizational pressure might depend on leaders’ expectations of a decline in followers’ commitment with protracted use of mass tactics. This is likely to motivate leaders to initiate terrorist campaigns to secure organizational survival. External organizational pressures might depend on increasing dissident campaigns’ fragmentation. This intensifies competition making leaders more likely to initiate terrorism so as to establish themselves at the forefront of their movements. The findings provide empirical support consistent with my claims and indicate no significant difference between civil wars and mass civil resistance movements with regards to these effects. Contrary to the common idea that the use of conventional violence should entail a higher willingness to engage in illegal violence against non-combatants, this finding suggests that conflict dynamics affect the decision to initiate terrorism and that terrorist campaigns have a coherent strategic logic across different types of mass dissent.

Do peacekeeping missions facilitate nonviolent political contention in post–civil war countries? The nonviolent expression of political grievances is a crucial part of the post–civil war peace-building process but is understudied thus far. We claim that the presence of peacekeepers significantly contributes to establishing a secure environment for nonviolent political contention, particularly nonviolent public protest. In addition, we claim that peacekeeping missions with personnel from countries with robust civil societies are more likely to promote nonviolent political contention because of prior socialization to civic engagement and bottom-top political participation. This is particularly true for UN police personnel (UNPOL), who both train local police forces and have the most direct interaction with protesters. We test our hypotheses using a newly crafted dataset on nonviolent protests in post–civil war countries and peacekeeping missions’ presence, size, and home-country composition. We find that peacekeeping missions’ presence significantly increases nonviolent protests in post–civil war country-years. This effect is largely explained by the presence of UNPOL from countries with strong civil societies. Our findings have important implications for our understanding of post–civil war political revitalization and policy implications for the composition of peacekeeping missions.

Bosnia and Herzegovina (BiH) experienced an unprecedented wave of non-sectarian anti-government protests in 2014. Although the key motivating factors generally highlighted such as economic marginalization and poor governance were common throughout Bosnia and Herzegovina, the protests did not extend to all parts of the country. Notably, despite very similar initial conditions in the two jurisdictions of the country, the Federation of Bosnia and Herzegovina (FBiH) saw major unrest with a large number of participants in many locations while subsequent protest mobilization was much more limited in the Republic of Srpska (RS). We take advantage of the variation in the responses from the two governments in the same country to evaluate how observed and anticipated government responses can shape the willingness to join dissident activity. We argue that variation in government responses and its impact on perceptions on prospects for successful collective action can help account for the differences in mobilization across the two entities. We test our expectations using a new data set on protest events, participants and government responses in BiH from January to April 2014. Our findings are consistent with the argument that coherent repressive government policies tend to suppress mobilization, while mixes of repressive responses and concessions from the government can encourage further mobilization. The results for FBiH show clear variation in protest following changes in government behavior, and are consistent the claim that repressive responses likely suppressed mobilization in the RS.

Fringe terrorism is common during nonviolent campaigns. We examine how this can modify the strategic environment between dissident groups and the state in ways that present both challenges and opportunities to moderate factions. Terrorism is intended to promote violent escalation in a conflict, but we argue that fringe terrorist activities in a nonviolent campaign under certain conditions can induce an advantage for well-organized moderate factions. The risk of escalation following terrorism can give the government more incentives to offer concessions to moderate campaign leaders if the movement can credibly prevent armed escalation. The ability to control and prevent violence is more likely when nonviolent movements have a hierarchical structure and a centralized leadership, as such campaigns are better able to prevent shifts by supporters towards violent fringes. Using new data on terrorist attacks by factions sharing the same overall objectives as ongoing nonviolent campaigns, we show that nonviolent campaigns are more likely to see substantial gains in spite of fringe terrorist activities when a movement has a hierarchical structure and a centralized leadership.