This article addresses scholarly deficiencies in identifying the conditions under which the desecularization of militaries takes place. To theorize this process, two militaries are studied, the United States and Israel. Arguably, six drivers sequentially generate the desecularization of the militaries: (1) Militaries largely mirror the growing influence of religion in the broader society. However, intramilitary drivers play their role in promoting/mitigating the extra-military mechanisms of desecularization. Thus, (2) organizational interests along with external constraints drive militaries to promote religious diversity, which may (3) lead to the empowerment of religious actors, and thereby to further desecularization through religious intolerance, and to (4) reliance on the spiritual and religious services provided by military chaplains, and jointly stimulate (5) the use of religion to motivate military sacrifice. By religiously increasing the symbolic value of military sacrifice, (6) religiosity becomes more naturally associated with good soldiering, thereby reshaping intramilitary hierarchies and, hence, further triggering desecularization.