The increasing focus on and interest in religion has been good news for the field of international relations, which has a history of secularist bias and neglect of faith-related factors. Although this post-9/11 interest has run the risk of becoming a temporary fad, a number of prominent scholars have managed to explore the role of religion in humanitarianism, security, world orders, and regional politics without stripping issues of faith of their content. Given the pace of international politics with all its crises and tensions, we are continuously in need of quality scholarship that can shed light not only on the current role of religion but also on its impact during the times when academics and politicians of the West are tuned to political materialism. Religion and International Relations Theory is a collection of essays that successfully establishes this link, exploring the contemporary religio-political sphere and its background and evolution.

Edited by Jack Snyder, the volume brings together 10 scholars who discuss their respective research and how that research can extend our perspective when it comes to religion and international relations. In his introduction, Snyder briefly reviews how three major paradigms—realist (Waltzian), liberal, and constructivist—can benefit from taking religion more seriously. It is worth noting that this chapter is the only one in the book that systematically engages the international relations theory agenda. The essays that follow are rich in content, and they make insightful observations about religion and international relations. However, the authors keep the focus on their own research rather than on the mainstream IR theory agenda. In that respect, the title of the book is slightly misleading. Also, whether constructivism is a theory or methodology should be further problematized; the authors take it in the former sense. However, constructivist methodologies do exist in realism and liberalism and are not necessarily outside of these paradigms. To give an example, Stephen Walt's Balance of Threat theory relies on perceptions and mental constructions in addition to material capabilities; religion is inevitably part of these concerns. If we narrow realism down to its Waltzian version without any attention to such wider interpretations of neorealism or to the possibilities of classical realism, then it is only to be expected that this paradigm will have to be excluded from discussion. The same goes for liberalism.

The chapters are diverse in terms of their approach and content, and there is no unifying method or frame, but this is to be expected in edited volumes. Daniel Philpott and Timothy Shah provide an account of secularism in the second chapter. They list possible meanings of secularism (p. 28), explain why the Western study of international relations remained secular for a long time and why this trend has recently been reversed. The chapter is mostly historical but provides a consistent narrative of the secular world order. Philpott and Shah call for a Kuhnian paradigm shift in the theory, arguing that “if international relations theory is to take into account religion's distinctive role … it must undertake a revision more radical than merely incorporating religion into its existing assumptions” (p. 51). This is in contrast to Snyder's claim, in the introduction, that “it will be worthwhile to consider how religion can be integrated into existing paradigms without violating their essential assumptions” (p. 6). The authors throughout the book have different opinions as to whether such integration is possible or not. Such disagreements are constructive and refreshing, and it would be interesting to see how the contributors would respond to one another and continue the debate.

In her chapter on different forms of secularism, Elizabeth Shakman Hurd provides “take away points for scholars of international relations” by drawing attention to politics of secularism. Agreeing with Philpott and Shah, Hurd calls for a “more nuanced account of the interplay between religion and politics” as an alternative to “realist, liberal and constructivist theories in which religion is considered a private affair” (p. 63). One wishes that the authors elaborated more on what the alternative could be, but it is understandable that within the constraints of space, this is not always possible. The third chapter is on religion and world order; Michael Barnett, drawing from experience in the field, situates religion in humanitarianism by “selectively sampling the history of humanitarianism to suggest some of the consequences of [religion's] neglect” (p. 96). Barnett's conclusion is different from Philpott and Shah's or Hurd's; he concludes by saying that he is “unconvinced that religion requires any special epistemology or ontology” (p. 109). The following chapter is an empirical review on religion and violence by Monica Duffy Toft. Toft focuses on religion and civil wars, and on the implications of these studies for rationality and deterrence.

Daniel H. Nexon's chapter reviews challenges posed by materialism, state-centrism and secularism. “Many of the contexts in religion, however, do not require us to understand the nature of religious experience,” Nexon states; “they involve the translation of religious experience into the kinds of activities we associate (rightly or wrongly) with politics” (p. 156). International relations scholars should indeed be aware of the fact that what they investigate are mere manifestations of various political theologies (as mentioned by Philpott and Shah), rather than the content of a religious tradition. The book is admirable in that respect; contributors stick to functional categories (e.g., humanitarianism, violence, governance), rather than claiming to engage the essence of specific religious traditions. Likewise, interdisciplinary cooperation with sociology, anthropology, religious studies, philosophy, and psychology is essential for the study of religion and international relations. Although the book does not represent such an interdisciplinary approach, the individual approaches point to the necessity of such a direction.

The only chapter that has a regional focus is by Il Hyon Cho and Peter J. Katzenstein. Cho and Katzenstein point to the Western bias in the studies of religion and secularism, and the disproportionate emphasis on Islam and the Middle East in the studies of foreign policy. Under the subtitle of “Religion in the Asian Past: No Privatization of Religion, No Secularization of Politics” (p. 171), the authors argue that the East Asian experience has been distinctive and that it has not been included in the Western academic narrative. These authors are understandably frustrated. Indeed, very few accounts of religion and international relations take into account Confucianism, Buddhism and the other Eastern traditions. Even fewer scholars go beyond the Middle East (which has 15% of the world's Muslims) when they investigate political manifestations of Islam.

In conclusion, the book is easy to read and is a great source for scholars who are interested in the roots of secularism and the resurgence of religion. The contributors also elegantly tie their research to international relations theory in their respective conclusions. Although the focus of the chapters, for the most part, is not on mainstream international relations theory, the authors raise important questions. It is also encouraging that scholars have recently started to use the concepts of “religion” and “international relations theory” together in articles and books. Existing IR paradigms have the potential to accommodate religion, and the works that bridge theory and religion are scarce. Given this gap, the next step for scholars of international relations is to systematically integrate religion into IR theory, addressing multiple debates within the paradigms and providing a comparative framework to facilitate debates. Unless we can establish such comparative and systematic frameworks, our discussions of the role of religion in international relations will remain incomplete.