One of the most striking features of the Ustasha regime is the extent to which religion, particularly Catholicism, was used as a means of political instrumentalization. Despite this, the sacralization of politics in the Ustasha state, and in particular the use of Catholic ritual and imagery as a form of regime legitimation, has received only peripheral attention in the existing literature. Although both radical nationalism and Catholicism were central ideas in the Ustasha ideological system, there are few, if any, studies exclusively dedicated to the subject. One reason for this perhaps is that many established Croatian historians have encountered difficulties in objectively addressing the subject of Catholicism under the Ustasha regime and in applying methodological and conceptual terminology. Frequently, historians have proven unable to distinguish between a clerical state (which the Ustasha state arguably was not) and a Catholic state (which it definitely was) and have therefore concluded that the ideology of the Ustasha state was secular with no religious influences. As a result, they have been unable to explain the support for the Ustasha movement among clericalist youth groups and village clergy or to account for the movement's rituals and ceremonies based on the altar and crucifix and their campaigns of morality and traditional “Catholic” values. Although the Ustasha movement was essentially secular in character, it actively appropriated “Catholic” values to mobilize the masses and gain public support.

This chapter focuses on how the Ustasha movement used religious ideas and concepts as a form of state legitimation. Rather than considering the role of the Catholic Church or its relationship with the Ustasha regime, a subject that has already been studied extensively in the existing literature, it instead explores the Ustasha movement's use of religious, specifically Catholic, ideas, imagery, morality, and language to legitimize its rule and genocidal policies toward the state's chief perceived “enemy,” the Serb minority. While the place of religion in Croat nationalism has often proved to be extremely important, the Ustasha movement transformed it into a central characteristic of their national ideology and ideological belief system.