^ so how many tribes were followers of Hazrat Musa AS? Or was it just one tribe? Even if it was just one tribe their "unity" factor is their religion and not ethnicity, their claim to land (which is now Israel) is based on religion not on ethnicity.
All the tribes of Israel were followers of Musa and were all descended from a common ancestor... Current Jews are of a single tribe, the rest being considered lost.
As for Israel, Jews consider themselves a race and a religion and most people accept that. Infact, as far as I know, Israel actually requires that the descendancy of Jewish citiznes be varified. For example, it took a while for Indian Jews to validate their claim to be Jewish.