"Judaism is primarily an identity, not a religion."

Uh, no.

Jewishness, being a Jew, is an identity or (in the context of this discussion)peoplehood. Judaism is and always has been a religion.

One can be a Jew without embracing or even knowing the first thing about Judaism. One can know a lot about Judaism without having any Jewish blood and without having converted. Go into most Reform congregations and I guarantee you many of the most knowledgable people there would be the non-Jewish spouses.

Which is a potent counter to the idea that intermarriage destroys Judaism: in fact, in many cases, it is the opposite. The non-Jewish spouse is the motivating force behind going to synagogue and having a Jewish home, whereas the "fully" Jewish adult often wants to escape his (usually not 'her') unpleasant memories of Jewish childhood.

Should all the Jewish "people" disappear tomorrow, or more to the point perhaps, had the Nazis been completely successful in their desire to rid the entire planet of Jews, Judaism the religion would still exist. Its texts and tenets would still be available to whoever wants to embrace them -- or embrace part of them.

And that very Judaism has always taken, borrowed, appropriated practices and values from the Gentile world surrounding it. The Passover seder was born out of the Roman symposium, for example.

In that sense, there is a connection between religion and peoplehood: if it's good enough for Judaism, it's good enough for the Jews.

Open doors and outreach -- especially the embracing of the intermarried and non-Halakhic -- are the keys to the survival of both the religion and whomever chooses to embrace it.