Look at your Hasidim today with their red hair, blue eyes etc. Look at your Ethiopians. Your fantasy of a semitic nation is not seen in the rainbow nation of Israel today. I wouldnt underestimate the Khazar factor- it may well have a large influence. Semitic dosen't mean Jewish and Jewish dosen't necessarily mean semitic- anti-semitism was synonymous with anti-Jews because in Europe there weren't any other semites wandering around in large groups so the name stuck. Anti-Jews would have been far more accurate but at the time it wasn't necessary to differentiate. Ultimatly being Jewish is about belonging to a secular or religious cult, either way its a cult and like any cult you are either in or you are out- group first, religion second so you can be secular but still be part of the cult unless you leave completely.
Key U.S. House Democrat cites troublesome issues in Iran nuclear deal (Reuters)
from the article: First and foremost a Jew