This thesis investigates the political fragmentation of post-war Bosnia and Herzegovina, focusing on the Bosniac Party of Democratic Action (SDA) and its role in state and nation-building, from the 1995 Dayton Agreement to the 2022 elections. Utilizing Pierre Bourdieu’s political field theory, tailored to Bosnia and Herzegovina’s multi-ethnic context, the study analyzes qualitative data from interviews, participant observation with SDA activists (as well as dissidents), and party documents, including programs and public statements. It identifies the key actors in the political field and examines how Bosniacs around SDA negotiate ethnic rivalries, external influences, and tensions between civic and ethnic nationalism in their pursuit of post-war state and nation-building. Offering new empirical insights into grassroots perspectives and a sociological framework, this work advances scholarship on post-Ottoman state and nation-building and the dynamics of political disintegration in diverse societies. Hamdija Begovic carries out sociological research with a special focus on Muslims and modernity. This is his PhD thesis.