His areas of specialization are Modern and contemporary history of India, historiography and historical method, Nationalism and sub nationalism, history of tribal and indigenous people of Northeast India. In 2008, Prof. Nag was Charles Wallace Fellow at the Centre of South Asian Studies, Univeristy of Cambridge (UK). He was a Commonwealth Fellow to UK during 2004-2005 and a Visiting Senior Research Fellow at Queen’s University, Belfast. He was also a Senior Fellow at Nehru Memorial Museum and Library, New Delhi for two years (2013- 2014). Dr. Nag has authored two Project Reports and over 60 Articles. With several published books and research articles, his book India and North East India: Mind, Politics and the Process of Integration 1946-1950 (Regency, Delhi, 1998) was nominated for Srikant Dutt Memorial Award for the Best Book on North East India in 2002 and, more recently, the book Contesting Marginality: Ethnicity, Insurgency and Sub nationalism in North East India (Manohar, New Delhi, 2002) was short listed for the new India Foundation Awards for the Best Book in Non-Fiction Category. He is also the member of the Govt. of India’s NCERT curriculum Revision Committee in Contemporary Indian Politics. He has been the OXFAM Consultant for North East Indian Affairs and a part of its India Disaster Report and Violence Mitigation and Amelioration Project and a contributor to its India Disaster Report. Currently, he is an Executive Member of the International South Asian Environmental Historians.