A survey of leading contemporary international relations (IR) journals published between 1980 and 1996 revealed that 6 out of 1,600 articles featured religion as an important influence. But things have changed this past decade. It is now impossible to maintain the notion that religion is irrelevant to international politics, for at least three reasons. First, the United States has had a difficult time imposing secular democracy around the world. Second, there has been the advent of a U.S. foreign policy model with President Bush that is officially secular yet inspired by a kind of Christianity. And third, a variety of religious movements and organizations with broad bases of national and transnational influence have become prominent in international politics. Some have suggested that the rise of religion confronts IR theory with a theoretical challenge comparable to that of the end of the Cold War or the emergence of globalization.

The central puzzle of my book The Politics of Secularism in International Relations is that of how we might begin to think about secularism, and eventually, secularisms in the plural, as forms of political authority in IR. What does this mean for IR theory and for our understanding of political Islam and the broad resurgence of religion? What kinds of politics follow from different forms of secular commitments, traditions, habits and beliefs? I argue that the secularist division between religion and politics is not fixed but socially and historically constructed. The failure to recognize the validity of this contestation helps to explain why IR—both in theory and in terms of actual practices of international politics—has been unable to come to terms with secularism and religion as forms of authority in world politics. Overcoming this problem—opening up the black box of secularism and digging into the complex negotiations that take place inside of it—allows for a better understanding of crucial empirical puzzles in international relations involving the politics of religion. Examples include the long-standing conflict between the United States and Iran, controversy over the enlargement of the European Union to include Turkey, the rise of political Islam, and the global resurgence of religion.

I approach secularism as a series of social and historical traditions—various sets of historical practices that have developed over time. These particular traditions of secularism both rely upon and help produce unique understandings of religion, political Islam, religious resurgence, “normal” politics and so forth. None of the divisions between religion and politics embodied in these secularist traditions are stable or universal. In fact, they are unstable; and even fundamentally contested, constantly being refined and redefined. To think about secularism in this way, I find it helpful to use Craig Calhoun’s suggestion that we approach nationalism as a discourse within which political struggles are conducted. When we adopt this insight, secularism becomes “not the solution to the puzzle [of politics and religion] but the discourse within which struggles to settle the question are most commonly waged.” Secularism is to an authoritative discourse, a language in which moral and political questions are settled, legitimated and contested. It is a form of political authority.

One implication of thinking about secularism in these terms is that it becomes clear that there are many traditions or varieties of secularism—Turkish Kemalism, French laïcité, American “Judeo-Christian” secularism. Each of these varieties of secularism represents a contingent yet enduring political settlement of the relation between religion and politics. Various forms of secularism both produce and are composed of authoritative settlements of religion and politics, while simultaneously claiming to be exempt from this process of production. This is a powerful move. Secularization then may be understood to be the combined social and historical processes through which a particular settlement becomes authoritative, legitimated and embedded in and through individuals, the law, the state, and other social relations, including international relations.

The central premise of my argument is that two specific trajectories, varieties or traditions of secularism, two strategies for managing the relationship between religion and politics, have been influential in international politics: laicism and Judeo-Christian secularism. Laicism refers to a separationist narrative in which religion is expelled from politics, and Judeo-Christian secularism refers to an accommodationist narrative in which Judeo-Christian tradition is perceived to be the foundation of secular democracy. These varieties of secularism don’t map cleanly onto one country or individual or another—both are present in different variations in different times and places. Both these forms of secularism are discursive traditions, following Talal Asad, collections of practices with a history. Each defends some form of the separation of church and state, but in a different way from the other, with a different justification and with different political consequences.

In developing the figure of Judeo-Christian secularism, I ask—to what extent have our forms of secularism inherited particular religious traditions? Or, rather, to what extent does Christianity, or post-World War II, Judeo-Christian tradition, animate contemporary, lived practices of secularism? It took Charles Taylor nearly 900 pages to answer this question in A Secular Age, so let me state briefly that I regard secularism as a series of lived traditions which are indebted to religious tradition and practice in significant ways, but the nature of their debts varies significantly with the form of secularism and the historical context in which it operates. This means that secularisms must be studied within their historical, cultural, and political contexts and not in the abstract. The secularisms that I write about are indebted to Christianity in interesting and complex ways, but laicism is also indebted to French Enlightenment thought, which is deeply anti-clerical.

These trajectories of secularism cannot be fully understood without reference to European and global history. They were created though human actions and beliefs and cannot be abstracted from the historical contexts and circumstances from which they emerged. While the secular traditions that interest me emerged out of and remain indebted to both the Enlightenment critique of religion and Judeo-Christian tradition, they also have been constituted and reproduced through global relationships, including negative representations of Islam.

But this argument has several implications for IR theory. My objective has been to bring debates from sociology of religion, philosophy, and political theory into international relations to refigure a field that has virtually ignored questions of how the categories of religion and politics shape international affairs. One implication of opening up this question of the politics of secularism is that it presents an alternative to realist, liberal and constructivist accounts of international relations that work on the assumption that religion has been privatized.

I challenge the assumption that after the Westphalian settlement, religion became privatized and thereby was rendered largely irrelevant to power politics. Instead, modern forms of secular authority emerged out of a specifically Christian-dominated Westphalian moral order. The influence of this specific tradition upon the Westphalian secular settlement makes it difficult to subsume the current international order into realist and liberal frameworks that assume that religion was simply privatized.

In other words, modern forms of secularism contribute to the constitution of a particular idea and practice of state sovereignty that claims to be universal in part by defining the limits of state-centered politics with “religion” on the outside. However, this attempt to delimit the terms and boundaries of the political and to define religion as a private counterpart to politics is a historically and culturally variable claim. It is also a highly politicized one. Different varieties of secularism create and perpetuate this claim about the limits of modern politics in different ways. From this perspective, they appear not as unchanging or obvious as we may have been inclined to see them before, but as contingent, yet firmly established, political settlements. These settlements operate below the threshold of public discourse and practice of state sovereignty. They may not be on the radar, but they should be, because they represent important constitutive elements of the theory and practice of modern sovereign authority.

A second contribution of this argument to IR theory involves the domestic/international question in relation to religion and politics. There has been a lot of great work done at this intersection. My contribution is to show how shared interests, identities and understandings of religion and politics that form at the domestic and regional levels become influential at the systemic level. This is constructivist theorizing that makes domestic politics a central part of the story, counteracting the tendency in IR, identified by Ole Wæver, Rodney Hall and others to “relegate domestic-societal interaction, sources of conflict, or societal cohesiveness to the status of epiphenomena.” This is a constructivist approach to the social, cultural and religious foundations of international relations.

If you accept my argument about the nature and significance of the politics of secularism, it becomes clear that the question often thrown about among students of religion and IR“What is religion and how does it relate to international relations theory/practice?”misses the point. For there can be no universal definition of religion. This is (as Asad argues) “not only because its constituent elements are historically specific, but because that definition is itself the historical product of discursive processes.” If the categories of “religion” and “politics” are themselves the products of complex cultural, historical and political negotiations, then the question that I would put front and center in this discussion is how do these categories take shape, become authoritative, and what are their political consequences in specific sets of historical circumstances?

Defining the secular and the religious is a political task. Religious beliefs and practices are interwoven with political authority in complex and changing ways that don’t necessarily align with state boundaries or conventional secularist assumptions. IR theorists need to examine the secularist assumptions about religion that are embedded in the hypotheses and the empirical tests of IR scholarship.