Gregory M. Reichberg

Research Professor

Gregory M. Reichberg
Work phone: +47 22 54 77 53
Mobile phone: +47 40 28 62 22

Research Interests

Issues at the intersection of peace, war, philosophy and religion.  


​Gregory M. Reichberg is Research Professor at the Peace Research Institute Oslo (PRIO) and Adjunct Professor in the Department of Political Science at the University of Oslo. He heads the Oslo-based Research School on Peace and Conflict (a consortium that offers doctoral courses) and is an associate editor of the Journal of Military Ethics.  From 2009-2012 he was director of the PRIO Cyprus Centre in Nicosia, where he coordinated research and dialogue activities on the search for a political settlement to the island’s division. Over the last ten years he has been engaged in religious dialogue on social/political issues, most recently in Iraq, where PRIO contributed toward drafting the Erbil Declaration (  

Reichberg's recently published work includes a monograph Thomas Aquinas on War and Peace (Cambridge University Press, 2017), and several co-edited volumes: 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 articles/book chapters include: "Historiography of Just War Theory" (in Oxford Handbook of the Ethics of War, 2017), "Jacques Maritain, Christian Theorist of Non-Violence and Just War" (Journal of Military Ethics, forthcoming 2017), "Jacques Maritain, l'Espagne et la guerre sainte" (Revue thomiste, 2015), and "The Morality of Nuclear Deterrence: A Reassessment" (in Nuclear Deterrence: An Ethical Perspective, Caritas in Veritate Foundation Working Papers, 2015).

Reichberg is a a member of the Pontifical Academy of Social Sciences (appointed by Pope Francis in 2016). He has been a faculty member in the philosophy departments at Fordham University and the Catholic University of America.


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All Publications

Peer-reviewed Journal Article

Reichberg, Gregory M. (2016) Jacques Maritain, l'Espagne, et la guerre sainte [Jacques Maritain, Spain, and Holy War], Revue Thomiste 115(2): 215–233.
Reichberg, Gregory M. (2013) The Moral Equality of Combatants - A Doctrine in Classical Just War Theory?, Journal of Military Ethics 12(2): 181–194.
Reichberg, Gregory M. (2012) Discontinuity in Catholic Just War? From Aquinas to the Contemporary Popes, Nova et vetera 10(4): 1073–1097.
Reichberg, Gregory M.; Henrik Syse & Endre Begby (2012) The Ethics of War. Part I: Historical Trends, Philosophy Compass 7(5): 316–327.
Begby, Endre; Gregory M. Reichberg & Henrik Syse (2012) The Ethics of War. Part II: Contemporary Authors and Issues, Philosophy Compass 7(5): 328–347.
Reichberg, Gregory M. (2011) Aquinas' Moral Typology of Peace and War, Review of Metaphysics 64(1): 467–487.
Reichberg, Gregory M. (2010) Aquinas on Battlefield Courage , The Thomist 74(3): 337–368.
Reichberg, Gregory M. (2010) Thomas Aquinas on Military Prudence, Journal of Military Ethics 9(3): 262–275.
Reichberg, Gregory M. (2010) Thomas Aquinas Between Just War and Pacifism, Journal of Religious Ethics 38(2): 219–241.
Syse, Henrik; & Reichberg, Gregory M. (2000) Protecting the Natural Environment in Wartime: Ethical Considerations from the Just War Tradition , Journal of Peace Research 37(4): 449–468.


Reichberg, Gregory M. (2016) Thomas Aquinas on War and Peace. New York: Cambridge University Press.

Book Chapter

Reichberg, Gregory M. (2016) Historiography of Just War Theory, in Lazar, Seth; & Helen Frowe, eds, The Oxford Handbook of Ethics of War. Oxford: Oxford University Press .
Reichberg, Gregory M. (2015) The Decision to Use Military Force in Classical Just War Thinking , in James Turner Johnson, ed., The Ashgate Research Companion to Military Ethics. Farnham: Ashgate (13–23).
Reichberg, Gregory M. (2014) Catholic Christianity: Historical Development, in Reichberg, Gregory M.; & Henrik Syse, eds, Religion, War, and Ethics: a Sourcebook of Textual Traditions. Cambridge: Cambridge University Press (76–103).
Reichberg, Gregory M. (2013) History of Just War Theory, in Hugh LaFollette, ed., International Encyclopedia of Ethics. Hoboken: Wiley-Blackwell .
Reichberg, Gregory M. (2013) Jacques Maritain, in Kristiansen, Ståle Johannes; & Svein Rise, eds, Key Theological Thinkers: from Modern to Postmodern. London: Ashgate (657–668).
Reichberg, Gregory M. (2013) Culpability and Punishment in Classical Theories of Just War, in Lang Jr., Anthony F.;O'Driscoll, Cian; & Williams, John, eds, Just War: Authority, Tradition, and Practice. Georgetown University Press(157–180).
Reichberg, Gregory M.(2011) Suárez on Just War Interpreting Suárez. : Cambridge University Press(185–204).
Reichberg, Gregory M.(2009) Norms of War in Roman Catholic Christianity World Religions and Norms of War. : (142–165).
Reichberg, Gregory M.;Popovski, Vesselin; & Turner, Nicholas(2009) Norms of War in Cross-Religious Perspective World Religions and Norms of War. : (303–315).
Reichberg, Gregory M. (2008) "Jacques Maritain", in Moderne Teologi: Tradisjon Og Nytnkning Hos Det 20. Århundrets Teologer. Oslo: (653–665).
Reichberg, Gregory M. (2008) Jus ad Bellum, in War: Essays In Political Philosophy. (11–46).
Reichberg, Gregory M. (2008) Just War and Regular War: Competing Paradigms, in Just and Unjust Warriors: the Moral and Legal Status of Soldiers. (194–213).
Reichberg, Gregory M. & Henrik Syse (2004) The Idea of Double Effect – in War and in Business, in Responsibility In World Business: Managing Harmful Side-Effects of Corporate Activity. Tokyo: United Nations University Press (17–38).
Reichberg, Gregory M. (2002) The Hard Questions of International Business: Some Guidelines from the Ethics of War, in Business Ethics and Leadership In Action. Cheltenham; Northampton: Elgar (304–318).
Syse, Henrik & Gregory M. Reichberg (1999) Conducting Business Amidst Human Rights Abuses: Some Lessons from the Just War Tradition, in Proceedings of the Tenth Annual Meeting of the International Association For Business and Society. London: SAGE (71–76).

Edited Volume

Reichberg, Gregory M.; & Henrik Syse, eds, (2014) Religion, War, and Ethics. New York: Cambridge University Press.
Reichberg, Gregory M.; Vesselin Popovski; & Nicholas Turner, eds, (2009) World Religions and Norms of War. Tokyo, New York, Paris: United Nations University Press.
Syse, Henrik; & Gregory M. Reichberg, eds, (2007) Ethics, Nationalism, and Just War: Medieval and Contemporary Perspectives. Washington, DC: The Catholic University of America Press.
Reichberg, Gregory M.; Henrik Syse; & Endre Begby, eds, (2006) The Ethics of War: Classic and Contemporary Readings. Oxford.
Gracia, Jorge; Bernard Schumacher; & Gregory M. Reichberg, eds, (2003) The Classics of Western Philosophy: A Reader’s Guide. Oxford.

Popular Article

Reichberg, Gregory M. (2004) Preemptive War: What would Aquinas say?, Commonwealth, 30 January.

PRIO Report

Faustmann, Hubert; Ayla Gürel; & Gregory M. Reichberg, eds, (2012) Cyprus Offshore Hydrocarbons: Regional Politics and Wealth Distribution, PRIO Cyprus Centre Report, 1. Nicosia: PRIO Cyprus Centre.

Report - Other

Reichberg, Gregory M. (ed.) (2014) The Peace Potential of Hydrocarbon Reseources: A Scoping StudyOslo: PRIO.

Blog Posts

The Iranian Nuclear Issue

Posted by Gregory M. Reichberg on Thursday, 18 February 2016

I have been tracking the Iranian nuclear issue for about ten years. Important in its own right, this issue also has significant implications for the international agenda on nuclear weapons disarmament. Let it be noted at the outset that the expression in question – “Iranian Nuclear Issue” – is a freighted one; it suggests the problem rested squarely with Iran, that the other countries involved (the P5 + 1 or more accurately the E3+3) were responding to a problem of Iranian making. Things were never so simple, as the issue was as much or perhaps even more a European and especially ...

Why Not Nuke ISIS?

Posted by Gregory M. Reichberg on Friday, 4 December 2015

Last week I received a call from a journalist doing background research for an article.  The journalist wanted to know whether I thought a nuclear weapon could be used against ISIS. I was admittedly surprised at this question.  But apparently the journalist queried me about this issue because others are asking about it as well. So why not nuke ISIS? First we must consider why this “alternative” is being considered at all. Unlike al Qaeda, ISIS controls a large swath of territory in Syria and Iraq, including two large cities, Raqqa and Mosul. Previously it was thought that nuclear threats ...

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