Its a con, that the worldly Israel uses to get people on its side, no country is sacrosanct, no country is superior or a special branch or an evolutionary mutaion that the Lord chose to be better than anyone else.
Except in the Tanakh, Yahweh enters into a covenant (Mosaic) with the Israelites stricter than the one he holds with humanity in general (Noahic). A covenant that ensures their special place among the peoples of the world.
For you are a people holy to the Lord your God. The Lord your God has chosen you out of all the peoples on the face of the earth to be his people, his treasured possession.