My research is broadly in religion and politics. It entails two broad modes of inquiry, one normative, the other empirical or sociological.

A major focus of my normative inquiry is reconciliation, which grew out of activist work in faith-based reconciliation around the globe. Between 2000 and 2006, I traveled regularly to Kashmir as a Senior Associate of the International Center for Religion and Diplomacy. I then helped leaders in the Catholic Church develop a vision of reconciliation in the Great Lakes region of Africa under the auspices of the Catholic Peacebuilding Network from 2009 to 2013 (see peacebuilding tab). My scholarly work on political reconciliation culminated in Just and Unjust Peace: An Ethic of Political Reconciliation (Oxford 2012), which derives from theological and philosophical roots an ethic of reconciliation that offers concrete guidelines to political orders facing pasts of authoritarianism, civil war, and genocide. I followed up this work with research in Uganda on the role of forgiveness in peacebuilding under the auspices of the Fetzer Institute. On reconciliation, I earlier edited The Politics of Past Evil: Religion, Reconciliation, and Transitional Justice (Notre Dame 2006) and later co-edited with Jennifer Llewellyn Restorative Justice, Reconciliation and Peacebuilding (Oxford 2014). With Gerard Powers, I co-edited Strategies of Peace: Transforming Conflict in a Violent World (Oxford 2010).

In Just and Unjust Peace, I argued that reconciliation is a way of conceiving justice. In the context of facing the past in political orders, this conception of justice was put forth by religious leaders and stood in contrast to the conception of justice advocated by the international community, which may be called the liberal peace and centers on rights, the rule of law, and judicial prosecution. In my current work, I aim to develop this conception of justice, broaden it to all of politics, and place it on Christian foundations. The central concept is what may be called the justice of right relationship. Some first installments of this work, exploring the meaning of justice in the Bible and contrasting it to the classical conception of “rendering due,” have now appeared in an article in Nova et Vetera titled “There is a Wideness in God’s Justice,” and in a chapter, “Giving Justice More Than Its Due,” in a forthcoming volume edited by Tom Angier and Matthew Levering, The Achievement of David Novak: A Catholic-Jewish Dialogue.

My work on justice has also explored religious freedom. In Spring 2019, I published Religious Freedom in Islam? The Fate of a Universal Human Right In the Muslim World Today (Oxford). I was co-director of the Under Caesar’s Sword project, which researched Christian responses to persecution around the globe and was funded by the Templeton Religion Trust. The project ran from 2014 to 2018 and its outputs are available on the project’s website (linked above and through tab). Since 2011, I have been an Associate Scholar of what is now the Religious Freedom Institute in Washington, D.C. I am Vice-Chair of the Board of Directors of the Institute of Global Engagement.

My first area of normative inquiry was the ethics of national self-determination, on which I published a piece in the philosophy journal, Ethics, in 1995, followed up by a book chapter on applications for law and institutions. In 2019-2020, I drafted a journal article that seeks to revise portions of my argument, correcting certain problems and placing the theory on a footing of natural law in the Thomist tradition, in contrast to the earlier pieces, which were situated in the Kantian tradition.

With Ryan T. Anderson, I co-edited A Liberalism Safe for Catholicism? Perspectives from the Review of Politics (Notre Dame, 2017), many of whose pieces are on issues of ethics, especially Church-state relations.

The other main stream of inquiry, empirical or sociological, has focused in recent years on explanations of the behavior of religious actors in global politics. It joins a cluster of political scientists who have conducted inquiry on religion in global politics in a discipline that had been largely secularized prior to around 2000.

I published “Explaining the Political Ambivalence of Religion,” in the American Political Science Review in 2007, an argument that I then expanded and incorporated into a book with Monica Duffy Toft and Timothy Samuel Shah, God’s Century: Resurgent Religion and Global Politics (Norton 2011), which documents a resurgence of religion in global politics over the past generation and seeks to explain why religious actors take on diverse political pursuits including democratization, peace, reconciliation, civil war, and terrorism. I have also published pieces on the role of the Catholic Church in global politics that join in this broad stream of inquiry.

My earlier focus of inquiry, in which religion also played a central role, looked at the origins and expansion of the modern system of sovereign states over several centuries, culminating in Revolutions in Sovereignty: How Ideas Shaped Modern International Relations (Princeton 2001).

The major books and articles in this scholarship can be found under the research tab. The articles have found homes in The American Political Science Review, World Politics, Ethics, The Journal of Religious Ethics, The Journal of Democracy, the National Interest, America, First Things, Political Studies, The Journal of International Affairs, The Review of Faith and International Affairs, Security Studies, and the Annual Review of Political Science.