(1) Why should Jews have chosen to "disappear over time". (2) Even the most cursory understanding of the history of the Jews in Europe will explain to you that it was routine for Jews to be deliberately treated differently by the majority population; it was they who wanted to keep Jews on the margins of their societies. They dictated where Jews were permitted to live, what livelihoods they were permitted to pursue, whether they could study in university or not, even where they were permitted to bury their dead and so on. Did you know that the first ghetto for Jews was in Venice and was formed in 1516? Not at the behest of Jews but because the Venetians decided it should be so.
Italian FM arrives in Iran to promote economic, political ties (Reuters)
from the article: Anti-Semitism in Europe: Jews are outsiders, not equals