Studies of religion and politics have begun to force their way into the mainstream of the discipline thanks to their increasing methodological sophistication and theoretical ambition in addition to the push of real-world events. In comparative politics, puzzle-driven structured comparison has yielded new insights into the rationality of religious behavior, the weight of path dependence in shaping religious values, and the play of socioeconomic factors in shaping religion's vitality. In international relations, recognition of the importance of religious identities and values in the play of international affairs has spelled an advance over realist caricatures that long discounted ideas as epiphenomenal and focused on the quest for wealth and power as the sole driver of international politics. But notable lacunae remain. The comparative subfield still needs to reckon with the noninstrumental aspect of religious behavior, the power of religion as an independent variable, and the differential appeal, persuasiveness, and political salience of religious ideas over time. The ir subfield must move beyond "paradigm wars" focused on whether religion matters in international politics in favor of more empirically grounded, structured comparison to illuminate when and why religion matters in international affairs.