• Davis Brown Maryville University of St. Louis, USA


A variety of domestic characteristics of states affect their propensities to armed conflict, including power, regime type, wealth, and economic strength (in addition to the dyadic characteristics of power differential, alliances, proximity, and the peace-learning process). Compared to these, religion is an understudied characteristic. Religions instill norms and ethics for the use of force just as secular ideologies often do. These war ethics influence the propensities to armed conflict of the states whose people and leadership adhere to those religions. Whether religious war ethics raise or lower those propensities depends on how permissive or restrictive they are. I show the empirical effect of those religious war ethics, working through states’ populations, on states’ probabilities to initiate armed conflicts against other states. The Christian war ethic is more restrictive and Christian populations are negatively correlated with states’ propensities to resort to force. The Islamic war ethic is more permissive and Muslim populations are positively correlated. The effect of religion is often strong and statistically significant, even after introducing conventional controls

Keywords: first use of force, Christianity, Islam, war ethics, populations


Aquinas Thomas, The Summa Theologica, trans. Fathers of the English Dominican Province, rev. Daniel J. Sullivan. 2 Vols. Chicago: Encyclopædia Britannica, 1952 [1274].
Aslan Reza, No God But God: The Origins, Evolutions, and Future of Islam, New York: Random House, 2005.
Bainton Roland H., Christian Attitudes Toward War and Peace: A Historical Survey and Critical Re-evaluation, Nashville, TN: Abingdon Press, 1960.
Bellin Eva, Faith in Politics, World Politics 60(2), 2008.
Bennett D. Scott, and Allan Stam, EUGene: A Conceptual Manual, International Interactions Vol. 26, No. 2, 2000.
Brown, Davis, The Sword, the Cross, and the Eagle: The American Christian Just War Tradition, Lanham, MD: Rowman & Littlefield, 2008.
Brown Davis, Judging the Judges: Evaluating Challenges to Proper Authority in Just War Theory, Journal of Military Ethics, Vol. 10, No. 3, 2011.
Brown Michael E., ed., Ethnic Conflict and International Security, Princeton, NJ: Princeton University Press, 1993.
Bsoul Labeeb Ahmed, Classical and Contemporary Muslim Juridical Views of Terrorism, Politics and Religion Journal, Vol. 8, No. 1, 2014, Belgrade.
Cashman Greg, What Causes War? An Introduction to Theories of International Conflict, Lanham, MD: Lexington Books, 1993.
Cederman Lars-Erik, Back to Kant: Reinterpreting the Democratic Peace as a Macrohistorical Learning Process, American Political Science Review, Vol . 95, No. 1, 2001.
Chayes Abram, and Antonia Handler Chayes, The New Sovereignty: Compliance with International Regulatory Agreements, Cambridge, MA: Harvard University Press, 1995.
Childress James F., Moral Responsibility in Conflicts: Essays on Nonviolence, War, and Conscience, Baton Rouge, LA: Louisiana State University Press, 1982.
CIA, National Basic Intelligence Factbook, Washington, DC: Central Intelligence Agency, 1976-1980.
CIA, The World Factbook, Washington, DC: Central Intelligence Agency, 1981-2008.
Copeland Dale C., Economic Interdependence and War: A Theory of Trade Expectations, International Security 20(4), 1996.
Correlates of War Project, National Material Capabilities Data Documentation, Version 4.0, 2010, (accessed 16.7.2011).
Correlates of War 2 Project, Colonial/Dependency Contiguity Data, 1816- 2002, Version 3.0, 2003, (accessed 17.7.2011).
Daniels Joseph P., Religious Affiliation and Individual International-PolicyPreferences in the United States, International Interactions, Vol. 31, No. 4, 2005.
Dark K.R., Religion and International Relations, New York: Palgrave Macmillan, 2000.
Donner Fred M., The Sources of Islamic Conceptions of War, In: Just War and Jihad: Historical and Theoretical Perspectives on War and Peace in Western and Islamic Traditions, ed. John Kelsay and James Turner Johnson, Westport, CT: Greenwood Press, 1991.
Engbers Trent A., Politics of a Polygamous People: How a Minority Religion Can Help Us Understand Religion and Politics in America, Politics and Religion Journal, Vol. 7, No. 2, 2013, Belgrade.
Eppstein John, The Catholic Tradition of the Law of Nations, London: Burns Oates & Washbourne, 1935.
Fearon James D., Rationalist Explanations for War, International Organization, Vol. 49, No. 3, 1995.
Fox Jonathan, Do Religious Institutions Support Violence or the Status Quo?, International Politics, Vol. 22, No. 2, 1999.
Ghosn Faten, Glenn Palmer, and Stuart Bremer, The MID3 Data Set, 1993-2001: Procedures, Coding Rules, and Description, Conflict Management and Peace Science, Vol. 21, No. 2, 2004.
Gibler Douglas M., International Military Alliances, 1648-2008, Washington, DC: Congressional Quarterly Press, 2008.
Gibler Douglas M., Meredith Sarkees, Measuring Alliances: The Correlates of War Formal Interstate Alliance Data Set, Journal of Peace Research, Vol. 41, No. 2, 2004.
Gill Anthony, Rendering unto Caesar: The Catholic Church and the State in Latin America, Chicago: University of Chicago Press, 1998.
Grewe Wilhelm G., The Epochs of International Law, trans. Michael Byers, Berlin: Walter de Gruyter, 2000.
Haas Mark L., The Ideological Origins of Great Power Politics, 1789-1989, Ithaca, NY: Cornell University Press, 2005.
Haas Mark L., The Clash of Ideologies: Middle Eastern Politics and American Security, New York: Oxford University Press, 2012.
Haas Michael, Societal Approaches to the Study of War, In: The War System: An Interdisciplinary Approach, ed. Richard A. Falk and Samuel S. Kim, Boulder, CO: Westview Press, 1980.
Hasenclever, Andreas, and Volker Rittberger, Does Religion Make a Difference? Theoretical Approaches to Impact of Faith on Political Conflict, Millennium, Vol. 29, No. 3, 2000.
Hassner Ron E., War on Sacred Grounds, Ithaca, NY: Cornell University Press, 2009.
Haynes Jeffrey, Religion and the Foreign Policy Making in the USA, India and Iran: Towards A Research Agenda, Third World Quarterly, Vol. 29, No. 1, 2008.
Henkin Louis, How Nations Behave: Law and Foreign Policy, 2nd ed., New York: Columbia University Press, 1979.
Huntington Samuel P., The Clash of Civilizations and the Remaking of World Order, New York: Simon & Schuster, 1996.
Information Please Almanac, New York: Simon & Schuster, 1947-1981.
Jevtić, Miroljub, Political Science and Religion, Politics and Religion Journal, Vol. 1, No. 1, 2007, Belgrade.
Johnson James Turner, The War to Oust Saddam Hussein: Just War and the New Face of Conflict, Lanham, MD: Rowman and Littlefield, 2005.
Johnston Douglas, Cynthia Sampson, eds., Religion, the Missing Dimension of Statecraft, New York: Oxford University Press, 1994.
Kalyvas Stathis, The Rise of Christian Democracy in Europe, Ithaca, NY: Cornell University Press, 1996.
Kelsay John, Arguing the Just War in Islam, Cambridge, MA: Harvard University Press, 2007.
Keohane Robert O., International Institutions and State Power: Essays in International Relations Theory, Boulder, CO: Westview Press, 1989.
Kepel Gilles, The Revenge of God, trans. Alan Braley, University Park, PA: Pennsylvania State University Press, 1994.
Kettel Steven, Has Political Science Ignored Religion?, PS: Political Science & Politics, Vol. 45, No. 1, 2012.
Khadduri Majid, War and Peace in the Law of Islam, Baltimore: Johns Hopkins Press, 1955.
Khong Yuen Foong, Analogies at War: Korea, Munich, Dien Bien Phu, and the Vietnam Decisions of 1965, Princeton, NJ: Princeton University Press, 1992.
King Gary, Langche Zeng, Explaining Rare Events in International Relations, International Organization, Vol. 55, No. 3, 2001.
King, Gary, and Langche Zeng, Logistic Regression in Rare Events Data, Political Analysis, Vol. 9, No. 2, 2001.
Koplow Michael J., Value Judgment: Why Do Americans Support Israel?, Security Studies, Vol. 20, No. 2, 2011.
Krasner Stephen D., Structural Causes and Regime Consequences: Regimes as Intervening Variables, International Organization, Vol. 36, No. 2, 1982.
Laitin David D., Religion, Political Culture, and the Weberian Tradition, World Politics, Vol. 30, No. 4, 1978.
Lobell Steven E, Norrin M. Ripsman, and Jeffrey W. Taliaferro, eds., Neoclassical Realism, the State, and Foreign Policy, Cambridge: Cambridge University Press, 2009.
Maoz Zeev, and Errol A. Henderson, The World Religion Dataset, 1945-2010: Logic, Estimates, and Trends, International Interactions, Vol. 39, No. 3, 2013.
Marshall Monty G., Ted Robert Gurr, and Keith Jaggers, PolityTM IV Project: Political Regime Characteristics and Transitions, 1800-2009, Dataset Users’ Manual, 2010, (accessed 17.7.2011).
Martin Richard C., The Religious Foundations of War, Peace, and Statecraft in Islam, In: Just War and Jihad: Historical and Theoretical Perspectives on War and Peace in Western and Islamic Traditions, ed. John Kelsay and James Turner Johnson, Westport, CT: Greenwood Press, 1991.
Mefttah Jilani Ben Touhami, and Mohammed Hussain Ahmad, Erroneous Similarities Between the Concept of Jihad and the Concept of Terrorism: (A Qur’anic Perspective), Politics and Religion Journal, Vol. 8, No. 1, 2014.
Miller Richard B., Interpretations of Conflict: Ethics, Pacifism, and the Just War Tradition, Chicago: University of Chicago Press, 1991.
Moravcsik Andrew, Taking Preferences Seriously: A Liberal Theory of International Politics, International Organization, Vol. 51, No. 4, 1997.
Mueller, John, Retreat from Doomsday: The Obsolescence of Major War, New York: Basic Books, 1989.
Neff, Stephen C., War and the Law of Nations: A General History, Cambridge: Cambridge University Press, 2005.
Norris Pippa, and Ronald Inglehart, Sacred and Secular: Religion and Politics Worldwide, New York: Cambridge University Press, 2004.
Nye Joseph, Soft Power, New York: Perseus Books, 2004.
Otis Pauletta, Religion and War in the Twenty-first Century, In: Religion and Security: The New Nexus in International Relations, ed. Robert A. Seiple and Dennis
R. Hoover, Lanham, MD: Rowman & Littlefield, 2004.
Philpott Daniel, Revolutions in Sovereignty. How Ideas Shaped Modern International Relations, Princeton, NJ: Princeton University Press, 2001.
Quackenbush Stephen L., and Michael Rudy, Evaluating the Monadic Democratic Peace, Conflict Management and Peace Science¸Vol. 26, No. 3, 2009.
Reiter Dan, and Allan C. Stam, Democracies at War, Princeton, NJ: Princeton University Press, 2002.
Rose Gideon, Neoclassical Realism and Theories of Foreign Policy, World Politics, Vol. 51, No. 1, 1998.
Rousseau, David L., Christopher Gelpi, Dan Reiter, and Paul Huth, Assessing the Dyadic Nature of the Democratic Peace, 1918-88, American Political Science Review, Vol. 90, No. 3, 1996.
Russett Bruce, Grasping the Democratic Peace: Principles for a Post-Cold War World, Princeton, NJ: Princeton University Press, 1993.
Russett Bruce, John Oneal, Triangulating Peace: Democracy, Interdependence, and International Organizations, New York: W.W. Norton, 2001.
Sachedina Abdulaziz A., From Defensive to Offensive Warfare: The Use and Abuse of Jihad in the Muslim World, In: Religion, Law and the Role of Force: A Study
of Their Influence on Conflict and on Conflict Resolution, ed. J.I. Coffey and Charles T. Mathewes, Ardsley, NY: Transnational Publishers, 2002.
Sandal Nukhet A., Religious Actors as Epistemic Communities in Conflict Transformation: The Cases of South Africa and Northern Ireland, Review of
International Studies, Vol. 37, No. 3, 2011. Sandal Nukhet A. & Patrick James, Religion and International Relations Theory: Towards a Mutual Understanding, European Journal of International Relations, Vol. 17, No. 1, 2011.
Sandal Nukhet A. & Jonathan Fox, Religion in International Relations Theory: Interactions and Possibilities, New York: Routledge, 2013.
Smith Tony, Foreign Attachments: The Power of Ethnic Groups in the Making of American Foreign Policy, Cambridge, MA: Harvard University Press, 2000.
Snyder Jack, Myths of Empire: Domestic Politics and International Ambition, Ithaca, NY: Cornell University Press, 1991.
Sonbol Amira, Norms of War in Sunni Islam, In: World Religions and Norms of War, ed. Vesselin Popovski, Gregory M. Reichberg, and Nicholas Turner, Tokyo:
United Nations University Press, 2009.
Souva Mark, and Brandon Prins, The Liberal Peace Revisited: The Role of Democracy, Dependence, and Development in Militarized Interstate Dispute Initiation, 1950-1999, International Interactions, Vol. 32, No. 2, 2006.
Stark Rodney, The Victory of Reason: How Christianity Led to Freedom, Capitalism, and Western Success, New York: Random House, 2005.
Stinnett Douglas M., Jaroslav Tir, Philip Schafter, Paul F. Diehl, and Charles Gochman, The Correlates of War Project Direct Contiguity Data, Version 3, Conflict
Management and Peace Science, Vol. 19, No. 2, 2002.
Suárez Francisco, S.J., On War [De bello], In: Selections from Three Works of Francisco Suárez, S.J., ed. & trans. Gwladys L. Williams, Ammi Brown, and John
Waldron, Oxford: Clarendon Press, 1944 [1612].
Sucharov Mira, Values, Identity, and Israel Advocacy, Foreign Policy Analysis, Vol. 7, No. 4, 2011.
Tibi Bassam, War and Peace in Islam, In: The Ethics of War and Peace: Religious and Secular Perspectives, ed. Terry Nardin, Princeton, NJ: Princeton University Press, 1996.
Tibi Bassam, Islamism and Islam, New Haven, CT: Yale University Press, 2012.
UN Definition of Aggression, G.A. Res. 3314 (XXIX), 1974.
U.S. Department of State, Annual Report on International Religious Freedom, 1999-2009, (accessed 2.2.2013).
Venugopal C.N., Polity, Religion, and Secularism in India: A Study of Interrelationships, Politics and Religion Journal, Vol. 7, No. 1, 2013, Belgrade.
Walt Stephen, The Origins of Alliances, Ithaca, NY: Cornell University Press, 1987.
Warner Carolyn, Confessions of an Interest Group: The Catholic Church and Political Parties in Europe, Princeton, NJ: Princeton University Press, 2000Weber Max, The Social Psychology of the World Religions, trans. H.H. Gerth and C. Wright Mills, In: From Max Weber: Essays in Sociology, ed. H.H. Gerth and C. Wright Mills, New York: Oxford University Press, 1958 [1922].
Webster Alexander F.C., Darrell Cole, The Virtue of War: Reclaiming the Classic Christian Traditions East and West, Salisbury, MA: Regina Orthodox Press, 2004.
Wollebæk Toset, Hans Petter, Nils Petter Gleditsch, and Håvard Hegre, Shared Rivers and Interstate Conflict, Political Geography, Vol. 19, No. 8, 2000.
The World Almanac and Book of Facts, Mahwah, NJ: World Almanac, 1968-1995.
World Values Survey Association, World Values Survey 1981-2008 Official Aggregate v. 20090901, 2009, (accessed 2.2.2013).