Åse Gilje Østensen is a political scientist focusing on the commercialisation of security and military tasks, civil-military relations, peace operations and defense and security politics. She is a post-doctoral researcher at CMI until 2018. Østensen holds a PhD in comparative politics from the University of Bergen. Key research interests include the role of private security and military industry in international operations, security sector reform, maritime security, United Nations peace operations and multilateral military interventions.

Østensen has conducted research on the role of private military and security companies in decision-making processes related to peace operations and security governance. She has investigated the political and practical implications of the privatisation of security in contexts ranging from Norway to Afghanistan and Iraq. She has extensive lecturing experience from the Royal Norwegian Naval Academy and the University of Bergen, and has published peer-reviewed articles, book chapters and policy papers.