Kumar has worked on strategic issues gaining reputation as a leading security expert. Dr. Kumar was a visiting professor and chair (Indian Ocean Studies) in the University of Dar-Es-Salaam (UDSM) from November 2017 to November 2019. He worked in the department of political science and public administration. In UDSM he taught Counter-terrorism, regional integration, peacemaking and conflict resolution. He also closely followed issues related to African politics, economics and security. Dr. Kumar has authored two books and has an edited volume. His first book Return from the Precipice: Bangladesh’s Fight Against Terrorism was published in 2012. His second book Multi-party Democracy in the Maldives and the Emerging Security Environment in the Indian Ocean Region was published in 2016. He has published over 30 research papers in reputed journals and edited books. He has delivered lectures on security issues both in India and abroad. He has participated and presented papers in national and international conferences.