They will be joined but that is yet future:
Ezekiel 37:16 Moreover, thou son of man, take thee one stick, and write upon it, For Judah, and for the children of Israel his companions: then take another stick, and write upon it, For Joseph, the stick of Ephraim, and for all the house of Israel his companions: (17) and join them one to another into one stick; and they shall become one in thine hand. (22) And I will make them one nation in the land upon the mountains of Israel; and one king shall be king to them all; and they shall be no more two nations, neither shall they be divided into two kingdoms any more at all:
I'll explain it all to you when we get there.
Won't it be wonderful when we know the whole truth and nothing but the truth?
Last time I checked the map Judah and Israel were united as one nation upon the mountains of Israel. I think the nation is called Israel.
But then I could be wrong about that too.
They are now intermingled together as one people.
In the future, they will be identified as by tribe and that is what is being discussed when the Kingdom is reunited both North and South.
What is most certain is that no Gentile nations are being blessed as Israelites.