I live in an area with a very large percentage of Jews from the USSR, and while there are plenty who did not marry other Jews, it seems like the majority did.
It’s always seemed quite interesting to me given that most of these people were (and still are) quite uneducated about Judaism, and almost none followed any kind of Jewish religious practices or rituals. Almost all of the men were uncircumcised and did not practice bar mitzvah, for example (with the exception of those from Muslim-majority countries in the USSR); though it seems like many decided to undergo those processes upon leaving the USSR and still married other Jews.
I know that Jews are an ethnic group as much or more so than a religious group, but given the Russification process as well as the enforced atheism, most Jews seemed to have become pretty “Russian” culturally and lost Yiddish and Jewish culture as well as the religion.
The main reason that I can think of for the continuation of Jewish-Jewish marriages is the persecution and discrimination Jews suffered in the USSR. It seems like persecution and discrimination often keeps people together as much as anything else; even Jews who didn’t know anything about Judaism or Jewish history knew that being Jewish was a hurdle they had to overcome in many areas of life, and marrying other Jews was probably a necessity because that was the main social class they mixed with and non-Jews often had discriminatory attitudes towards them anyway.
What are the other reasons for this? Did parents and grandparents maintain that their children had to marry other Jews, even though Judaism and Jewish identity were basically erased?
PS: I’m talking mostly about Russia, Ukraine, Belarus, Moldova, Armenia and other Christian, “European” countries. I’m aware that the situation of Bukhari, Kavkazi and other Jews in Muslim-majority countries was different.