Chapter 1 lays out the main argument of the book, asserting that insurgent groups’ dependence on their support networks ensures that to a certain extent they are obliged to respect their supportive constituencies’ ideological preferences and normative expectations. Relationships between armed groups and their constituencies are not stable and change over time as conflicts develop, ensuring that insurgent groups can also lose popular support. This chapter argues that this important dimension of insurgency is sometimes overlooked in favour of structural, ideological or resource-oriented analyses of conflict. It specifies how the book uses (or not) specific terminology and concepts like terrorism and Kurdistan. The chapter proceeds to discuss the difficulties in working with data in research on insurgencies. It argues that all forms of data – quantitative and qualitative – have inconsistencies and it backs the call for greater data transparency in conflict studies. It elaborates on some of the specific challenges related to data reliability on the conflict in Turkey. It describes the interview process, discusses the representativeness of the interview sample and the challenges of fieldwork. It finishes by outlining the structure of the book.