The factor that stimulated the thought of ethical justification of warfare in medieval Europe was among others expansion of Islam. At the beginning of the Islamic religion, its believers were deeply convinced by the ideas coming from the pages of Koran dictated by prophet Mohammed, the words which encouraged them to convert infidels. The fact is that during the lifetime of Mohammed, Muslims bent to their own will many Arabic tribes and just after his death they had a greater part of the Arabian Peninsula in their hands. In 711 they crossed the Strait of Gibraltar and started conquering the Iberian Peninsula. In the meantime, in Europe, people who, on account of their public role, were supposed to have a wider perspective of the world issues, were aware of the dangers which Islam caused. The fight for preservation of the Latin civilization caused thus far an unprecedented inner consolidation of armed, political and intellectual forces of those times. In this way the epoch of the crusades began.
Although the Council‘s declaration Nostra aetate has been absorbed by the magisterium, there are new challenges suggesting its acknowledgement and further development. The document’s significance resides in its foundation on Romans 9-11 and in the fact that it has been promulgated at all, in spite of enormous resistance in the years ahead. No. 528 from the Catechism of the Catholic Church rises up out of various official statements with respect to this topic: The three wise men from Jesus’ Epiphany are typical representatives of the pagan religions who have to turn to the Jews in order to receive “from them the messianic promise”. This insight corrects a romanticizing pluralism of religions as it becomes manifest in the terminology of the three “Abrahamic religions”. A further development of Nostra aetate should include two aspects: Overcoming the narrowing down of Judaism and Christianity as a “religion” without refeRence to realities like “the land”, and, secondly, deepening the theological understanding of the referral of Christianity towards Judaism, particularly in connection with the term “People of God”.