Against the backdrop of a widespread hardening of international borders, the proposed paper makes two core claims: (1) this is a problem to which the philosophy of religion can and should respond; (2) philosophical pragmatism, particularly that of C.S. Peirce, can make a vital contribution to this response. Philosophically, the problem of hardening borders manifests itself in three ways: epistemologically, via a normative/empirical gap concerning public perceptions of borders relative to the empirical conditions in specific border spaces; topologically, via the complex imbrications of continuity and discontinuity that borders represent; and semiotically, via the constitutively semiotic character of borders and their paradoxical capacity to be emblematic of/exceptional to wider cultural dynamics. What makes this problem religiously relevant is the fact that the hardening of borders stems fundamentally from a transformation of Westphalian sovereignty, whose religious dimension lies in both the political-theological roots of sovereignty and the cultural relevance of contemporary religious communities as indicating—and potentially responding to—contemporary sovereign transformation. That Peirce's pragmatist legacy can make an innovative contribution is demonstrated in three areas of Peirce's thought: (1) a logic of relations predicated on the interrogation of likeness and alterity—an inescapable task when analyzing borders—in terms of systems discernible diachronically and empirically; (2) sustained topological engagement of continuity and discontinuity in cartographic terms, including that of lines that bisect otherwise undifferentiated spaces; (3) a semiotic system attuned to both paradox and religious engagement. Taken together, these resources integrate empirical and normative analyses, engage religious beliefs and practices nonreductively, and disclose resources by which the philosophy of religion can better engage with diverse social and cultural transformations.