Gregory M. Reichberg is Research Professor at the Peace Research Institute Oslo (PRIO). He has held appointments in political science at the University of Oslo and in philosophy at the Catholic University of America, Fordham University, and MF-Norwegian School of Theology, Religion, and Society. From 2012-2020 he headed the Oslo-based Research School on Peace and Conflict, and from 2009-2012 he was director of the PRIO Cyprus Centre in Nicosia, where he coordinated research and dialogue activities in search of a political settlement to the island’s division. He has also led dialogue activities involving Iran, Iraq, and Lebanon.

Reichberg co-leads (with Jovana Davidovic) PRIO's research project, "Ethical Risk Assessment of AI-enabled Weapons: A Systems Approach," funded by the Research Council of Norway. He previously led "Warring with Machines: Artificial Intelligence and the Relevance of Virtue Ethics," a four year (2021-2023) project funded by the Research Council of Norway.

A member of the Pontifical Academy of Social Sciences since 2016, in 2021 he was appointed consultor to the Holy See’s Dicastery for Promoting Integral Human Development, headquartered in Vatican City, where his contribution focuses on disarmament, the ethical implications of new military technologies, and broader issues of war and peace.

His writings include a monograph Thomas Aquinas on War and Peace (Cambridge University Press, 2017), named an “Outstanding Academic Title 2017” by Choice magazine. He has also published several co-edited volumes, including Robotics, AI, and Humanity: Science, Ethics, and Policy (Springer, 2021); Religion, War, and Ethics: A Sourcebook of Textual Traditions (Cambridge University Press, 2014); World Religions and Norms of War (United Nations University Press, 2009); and The Ethics of War: Classic and Contemporary Readings (Blackwell Publishing, 2006).

His recent publications include “Luigi Sturzo (1871-1959),” in Just War Thinkers Revisited: Heretics, Humanists and Radicals, Routledge (2025); “Ethical Analysis of AI-based Systems for Military Use” (with Henrik Syse) in Artificial Intelligence, Ethics, and the Future of Warfare, Routledge (2024); “Toward a Thomistic Theory of Attention,” The Thomist (2024); “The Doctrinal Status of Just War in the Contemporary Teaching of the Catholic Magisterium,” Studies in Christian Ethics (2024); “Philosophical Debate on Deterrence,” in Forbidden: Receiving Pope Francis’s Condemnation of Nuclear Weapons, Georgetown University Press (2023); and “Risks of Weaponry Integrated with Artificial Intelligence,” Existenz (2022).