This book examines the impact of applying the "e;terrorist"e; label to a group's choice to resort to violence within an ethnonationalist conflict.Using the Partiya Karkeren Kurdistane (PKK) in Turkiye as a primary case study, the book interrogates the socio-political ramifications of the Turkish government's decision to label the PKK as a terrorist organisation. Drawing on longitudinal interviews, newly opened Turkish and Kurdish archives, media frame databases, and casualty logs, it maps five decisive moments: the 1984 guerrilla launch; Abdullah Ocalan's 1999 arrest; the 2012-2015 peace talks; Kobani's stand against ISIS in 2015 in a town in Syria; and the 2025 stand down. Furthermore, the study's empirical analysis and discussions reveal that the invocation of the label "e;terrorist"e; against the PKK places the group's actors and sympathisers in a situation that makes it harder for them to engage in peaceful means of resolving the conflict. Using four waves of interviews with Kurds in Turkiye and Syria spanning over a decade, the book offers dynamic insights into how attitudes towards the PKK and the "e;terrorist"e; label have shifted over time.This book will be of interest to students and scholars of terrorism and political violence, ethnic conflict, critical security studies, and international relations.