Terrorism has arguably been one of the defining factors of our age. It frequently makes headlines, threatening or attacking governments, private business and ordinary citizens. And in many parts of the world, it has been one of the most important threats to peace, security and stability. But what does this exactly mean? What is the nature of this threat? Who or what is threatened, how, by whom and why? What can be done about it or how can we at least limit the impact of terrorism and make sure that terrorists do not make headlines and manage to scare us? These are just a handful of questions that will be addressed in this course that consists of three parts. First it focuses on the essence of terrorism as an instrument to achieve certain goals, in addition to an exploration of this phenomenon and the difficulties in defining it. The second part provides an overview of the state of the art in (counter) terrorism studies. Since ‘9/11’ terrorism studies have grown exponentially, reflecting the rise in perceived threats. But what has academia come up with? What theories, assumptions and conventional wisdom has it produced that could be of help in understanding terrorism and dealing with it? The most interesting results are examined and compared with empirical evidence with the aim to either stress their importance or to debunk them as myths. The final part looks into the implications and possibilities for policy making. The course ends with a module specifically designed to address one of today's most topical issue: the foreign fighter phenomenon.