HaKatan > For example, Syrian Jews have a rather different culture (and language) than do Hungarian Jews, for example. And the land (until Mashiach comes) is no different than Matza on Pesach. As even Rabbi Dr. Soloveitchik noted, �EY is one mitzva among the mitzvos�.
You are right, but this does not exclude that we are also one nation with multitude of Jews who are to some, or large, degree assimilated. This is especially seen at the time of persecution, whether Shoah, USSR, or other times. R Schach says that Hashem had to introduce Arab hatred towards early non-R Zionists – because otherwise, they would have enrolled in universities of Beirut and Cairo and intermarried … from this, we see that R Schach definitely considered these Zs part of the nation that Hashem is protecting. As to R Soloveitchik, he also talks about these nonR Jews, including in the time of megillah coming back during times of persecution.