No it is not simply a victim mentality.
There is more than enough evidence that anti-Semitism was a cancer within all of Europe which led to the Holocaust. And the Western nations did nothing, or next to nothing, to save the Jews from extermination. Indeed Jewish refugees were barred from entering the USA at that time.
Anti-Semitism has a long history going back to the dispersion of the Jews. There is no question that in the New Testament, God holds the unbelieving Jews accountable for the crucifixion of Christ (even though it was a part of God's plan of salvation). But that should not have automatically resulted in hatred for the Jews. But that is exactly what happened:
"The attitudes expressed in the [Catholic] theological literature of the time were ultimately even more important. Eusebius of Caesarea took every opportunity to stress God's "rejection" of the Jewish people. John Chrysostom hurled bitter invective at the Jews and denounced Christians who associated with them and visited synagogues. Jerome delighted in emphasizing the faults, real or imagined, of ancient and contemporary Jews. Most important was Augustine , bishop of Hippo in North Africa. He put forward the theory, which long remained part of Christian theology, that it was the will of God to keep a remnant of the Jews alive in a degraded state as living witnesses of the Christian truth...
In theory this [that faith could not be forced] remained the basic papal policy for many centuries, although in practice it was often flagrantly violated. In a series of Church councils, meeting in Toledo throughout the seventh century, the Visigothic kingdom of Spain, which had by this time become Catholic, passed a series of increasingly stringent laws to compel the Jews to join the Church or leave the country...
https://www.jewishvirtuallibrary.org/the-catholic-church
We even know of Martin Luther's attacks on the Jews. But before that the Catholic Church was attempting to force Jews to become Catholics upon pain of death or torture.