NSF Award Abstract Proposal ID: 2116678/2116693/2116746 NSF Program: Security and Preparedness Title: Collaborative Research: Ghosts in the Machine: Militias and Paramilitaries in Militarized Interstate Conflicts New Title: Collaborative Research: Militias and Paramilitaries in Militarized Interstate Conflicts This project will determine when non-state actors such as militias and paramilitaries influence the duration, severity, and outcomes of militarized interstate conflicts. These actors have been increasingly active in interstate conflicts since the end of the Cold War. The project will produce a new data set on the involvement of militias and paramilitary actors in militarized interstate conflicts. The project will provide systematic evidence on the impact of these non-state actors on conflict behavior based on empirical analyses of this new dataset. The results of this project will contribute to improving our understanding of when and how domestic actors such as militias and paramilitaries influence the decisions of states in international disputes that can lead to escalation and war. The project will develop and test theory on the actions that militias and paramilitaries undertake that contribute to the escalation and duration of militarized interstate conflicts. A new and comprehensive dataset on the organizational structure and event-level military actions of militias and paramilitaries in militarized interstate conflicts will be collected for the period 1816 to 2017. Statistical analyses of the new data set will be conducted to test theoretical propositions. The results of the project will advance basic research on the domestic sources of international conflict and war, the strategic use of non-state actors by state leaders to coerce and confront international adversaries, and whether states can effectively control these militias and paramilitaries in wartime and in the termination of armed conflicts. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.