From 1994 to 2004 he held various positions in UK academic institutions at the University of Ulster in Belfast and as a Research Fellow at the Institute of Governance, Public Policy and Social Research, as well as at the Institute of Irish Studies, both at the Queen’s University Belfast. His most recent book, The IRA and Armed Struggle, which is based on the widest sample of personal interviews with former IRA members ever carried, was published by Routledge in 2007. He is book review editor for the journal Democracy and Security and is a member of the editorial board of Studies in Conflict and Terrorism and Terrorism and Political Violence. He is a member of the European Commission Expert Group on Violent Radicalisation.