...Many Catholic priests, mainly of the lower rank, took an active part in the murder operations. Generally speaking, the reaction of the Catholic church was a function of military and political developments affecting Croatia; when the standing of the NDH regime was weakening and the war was drawing to an end, protests by the church against Ustasha crimes became more and more outspoken.

This was not a case in the earlier stages. A bishop's conference that met in Zagreb in November 1941 was not even prepared to denounce the forced conversion of Serbs that had taken place in the summer of 1941, let alone condemn the persecution and murder of Serbs and Jews. It was not until the middle of 1943 that Aloysius Stepinac, the archbishop of Zagreb, publicly came out against the murder of Croatian Jews (most of whom had been killed by that time), the Serbs, and other nationalities.

The Vatican followed a similar line. In the early stage, the Croatian massacres were explained in Rome as "teething troubles of a new regime" (the expression of Monsignor Domenico Tardini of the Vatican state secretariat). When the course of the war was changing, the leaders of the Catholic church began to criticize the Ustasha, but in mild terms; it was only at the end, when Allied victory was assured, that Vatican spokesmen came out with clear denunciations. In some instances, Croatian clerics did help Jews. Their main effort was to save the lives of the Jewish partners in mixed marriages, and most of these did in fact survive. The church also extended help to the Zagreb Jewish community in providing food, medicines, and clothing for Jews in the concentration camps.