I don’t believe the Torah is literally true, but if I did I would believe that God promised Israel to the Jewish people.

I say “we come from Israel” because that’s where Jewish peoplehood and religion developed.

By “Jewish converts from Europe” I assume you’re referring to the Khazar Theory, which has been debunked by genetic analyses showing that the patrilineal side of most Askhenazi Jews shows origins in the Levant. It appears there was a genetic bottleneck event in which a very small number of (possibly Italian) women intermarried with Jews, and a very large proportion of Ashkenazi Jews descended from this group. You can see this in any one of the numerous genetic studies done.

But regardless of whether European Jews converted or not, Jewish law considers converts just as Jewish as anyone else.

And even if one doesn’t care about Jewish law and believes that European Jews should stay out of the Middle East, most Jewish Israelis are descended from Middle Eastern and not European Jews.