This paper challenges the historical consensus on the liberal stance of US bishops on post-war Jewish-Christian relations. By examining ecclesiological, political, and doctrinal factors shaping both individual bishops and their collective body, the NCWC, I reassess the doctrinal framework granted to interfaith relations within the broader concern over "religious indifferentism," typical of Pius XII's pontificate after 1948. As late as Oct. 1962, the NCWC Administrative Board opposed reintroducing the "Jewish Decree" to the Council agenda. Did US bishops remain deeply Pacellian? To outline NCWC's ambivalence, I serially analyse its decisions from the 1943 "Principles of Intercredal Cooperation" to 1965, contextualizing them within the Church hierarchy - toward Rome (papacy, Roman congregations, apostolic delegate) and toward the bishops. As a collective body, NCWC took conservative stances. Yet, pre-VaticanII limits on collegiality and focus to preserve episcopal authority within one's juridiction, enabled local adaptations and nationwide diversity. Rather than simply obeying Rome, the NCWC anticipated Roman concerns about the National Conference of Christians and Jews (NCCJ) in 1947, overcomplied with Cicognani's enquiry following the Holy Office warning in 1950, and issued its own reservations in the mid-1950s. Avoiding NCCJ as an interfaith public platform, NCWC preferred informal contacts with the Synagogue Council of America and the National Council of Churches. Public engagement remained cautious: gentlemen's agreements prevailed, joint statements were avoided, and discourse on religious difference was tightly controlled by the Adm. Board according to the 1943 Principles. Meanwhile, the Dept of Social Action, handling most interfaith interactions, grew increasingly at odds with such strict separation between doctrine and civic cooperation. Yet, the 1943 Principles had a dual effect, as they were still invoked in 1965 against the newly promulgated NostraAetate.