Israel was the Northern Nation, Judah the Southern. Israel was taken away and is lost to History. Judah went to Babylon, came back as worshippers of the Babylonian Talmud, not the Torah.
Judah would be the Nation if they were to be Historically correct.
God will not need the US to prop them up, they would be an astonishing sight, living in Peace with their neighbors if they were placed here by YHVH.
God has not lost Israel.
They still exist and God knows who they are.
Revelation 7 addresses the fact that Jews from all 12 tribes of Israel are sealed during the Tribulation.