Triggers of State-Led Mass Killing.

This article investigates the specific events that trigger state-led mass killings against civilian populations, analyzing data from all countries between 1989 and 2017 using event coincidence analysis (ECA). It identifies seven potential triggers grouped into three categories: changes in armed conflict conditions (government battle losses, rebel civilian killings, conflict spillover), popular civilian mobilization (nonviolent and violent protests), and direct threats to leadership integrity (attempted and successful coups). The study finds that significant government battlefield losses and successful coups are the most powerful and consistent triggers of mass killings, especially in autocratic regimes characterized by low rule of law and high political instability. In contrast, escalations in rebel civilian killings, conflict spillover, and protests generally do not systematically trigger mass killings, though violent protests have a weak triggering effect in autocracies. The findings suggest that incorporating these trigger events into early warning systems can improve atrocity prevention efforts by providing short-term indicators of mass killing onset within high-risk structural contexts.