Dr. Huseyn Aliyev is a Senior Lecturer in the School of Social and Political Sciences at the University of Glasgow in Scotland. His area of expertise is Ukraine and Russia (particularly the North Caucasus region). His current research interests are civil war dynamics, non-state armed groups, violent mobilization and the radicalization and demobilization of armed groups. In this interview Dr. Aliyev discusses paramilitary groups in Ukraine and the nearby border regions of Russia and their involvement with the Russian invasion against Ukraine. Here is his biography. https://www.gla.ac.uk/schools/socialpolitical/staff/huseynaliyev/#biography
This is a link to his new book, "Who Fights for Governments?". https://www.bloomsbury.com/uk/who-fights-for-governments-9781350498419/