The dissertation, Repression and Network Science: Tools in Fight against Terrorism, explores what determines post-terror repression in democracies and what alternative tools network science may ultimately reveal to for compelling authorities to rely on repression less. To do this three papers concentrate on some aspect of the question at hand. The first chapter is empirical, using a panel, cross-section design to evaluate under what conditions democracies use state terror or state repression following terrorism. Chapter 2 takes the opposite view, using high-powered statistics to evaluate a single case. At question is the tool in use more than the terrorist network under inspection. Network science is fascinating, disappointing, and daunting, offering a world of potential with few advances, in the area of theoretical evaluation, and therefore large amount of work ahead. Chapters 2 and 3 explore various aspects of what is needed with 2 focusing on improving methods in network statistics and 3 stressing the need for further development of theories for testing with improved statistical models.