People confuse religion with ethnicity all the time. But somehow most people don't assume Roman Catholics are all Italian, I mean Romans were Italians so... Anyway, legend has it the twelve tribes of Israel each had distinct features , I don't know because I wasn't there. There are 2 points I find funny about the topic of Jews and Semites. First the children of Israel if they ever existed didn't call themselves Jews, generically they would be described as the children of Israel. Specifically by their tribal name Children of Dan or of the tribe of Judah or of Shabaz. So it was Shakespeare who popularized the word Jew.
Now for the other funny part the word Semitic all definitions say Semites are a broad group of people, which include geographical origin and languages. These include not only the Palestine area but Arabia, Syria and others, the languages considered Semitic are Arabic, Aramaic/Syriac, Hebrew, and others. The person who coined the term Anti-Semitic was a German who hated Jews. This is funny on many levels, first as you point out the likelihood of ancestral children of Israel surviving centuries after the diaspora is slim. That these Caucasoid European people most likely remnants of Roman outposts could in any way be related to the 12 tribes is also very slim. So are they Jews? Yes they are Jews, however saying Jews are Hebrews is another thing altogether. As far as the political aspect of your question, good luck with that. As long as the majority of people on this pale blue dot believe in invisible sky giants they aren't going to stop killing each other over who they think god's favorite children are. They will always think they are it, and will kill those who do not agree.