My research analyzes how and why governments and opposition groups use violence, particularly terrorism, to accomplish their goals and the implications their choices and interactions have on national & international security. I am most interested in two "big" questions. First, how terrorism is used as a tactic for radicalization, recruitment, and political mobilization. Second, how countries' domestic politics influences dissidents' tactics and violence. In a Monkey Cage post I show that the combination of changes in ‘the caliphate’ & French domestic politics explains the November 13, 2015 ISIS attack on Paris.