NATIONS FOUNDED BY THE GOD ARE HARD TO FIND, FOR ONLY ANCIENT ISRAEL IS RECOGNIZED AS BEING FOUNDED BY GOD. The Israel Of Today Is Not Considered To Be The Israel Of Old Because It Does Not Contain The Twelve Tribes That Came Out Of Egypt. Many people nevertheless are prepared to accept that modern-day Israel is the nation of God, but most people do not.
Those who believe in the idea of British Israelism believe that England has been favored by God above the other nations. This is because the Bible says that Jacob will become a nation and a company of nations and this has been interpreted to mean England and the British Commonwealth. Also the British Israelite advocates believe the Throne of King David has become the British Throne and this is what is meant by his line lasting forever.
A nation and a company of nations
And God said to him, “I am God Almighty: be fruitful and multiply; a nation and a company of nations shall come from you, and kings shall spring from you. (Genesis 35:11)
The House of Judah
Then rose up the heads of the fathers’ houses of Judah and Benjamin, and the priests and the Levites, every one whose spirit God had stirred to go up to rebuild the house of the Lord which is in Jerusalem. (Ezra 1:5)
Now these were the people of the province who came up out of the captivity of those exiles whom Nebuchadnezzar the king of Babylon had carried captive to Babylonia; they returned to Jerusalem and Judah, each to his own town. (Ezra 2:1)
David's throne shall endure as the sun
Once for all I have sworn by my holiness; I will not lie to David. His line shall endure for ever, his throne as long as the sun before me. (Psalm 89:35-36)
David shall never want a man to sit upon the throne of the house of Israel
For thus says the Lord: David shall never lack a man to sit on the throne of the house of Israel. (Jeremiah 33:17)
The king's daughters into the land of Egypt
But Johanan the son of Kareah and all the commanders of the forces took all the remnant of Judah who had returned to live in the land of Judah from all the nations to which they had been driven— the men, the women, the children, the princesses, and every person whom Nebuzaradan the captain of the guard had left with Gedaliah the son of Ahikam, son of Shaphan; also Jeremiah the prophet and Baruch the son of Neriah. And they came into the land of Egypt, for they did not obey the voice of the Lord. And they arrived at Tahpanhes. (Jeremiah 43:5-7)
The Christadelphians website states:
The Kingdom of God was the Kingdom of Israel in the past (2 Chron. 9:8). It was overturned because of their disobedience, but the Kingdom will be re-established (Ez. 21:25-27). The Kingdom will return to Jerusalem (Mic. 4:8) when Jesus reigns there on David's throne (Lk. 1:32). 
Ephraim is interpreted as the British Empire and the United States said to be the remnants of the Tribe of Manasseh.
The name Ephraim is sometimes used representatively in Scripture for the entire northern kingdom, though it can also refer solely to the descendants of Joseph’s son of that name—prophesied to become a “multitude of nations” (Genesis 48:19). Remarkably, this promise to Ephraim was fulfilled in the British Empire and Commonwealth. 
Ephraim’s older brother Manasseh was also prophesied to become a great nation (same verse), separating himself from the multitude of nations. This prophecy would be fulfilled in the formation, growth and dominance of the United States of America. 
Those who find us in the passage point to Ezekiel 38:13 which says that “the merchants of Tarshish and all its villages” (or “young lions” depending on translation) will speak out against the invasion. The argument is that Tarshish is Britain and the “villages” or “young lions” are the English speaking nations like the U.S. and Australia that were founded by British immigrants. 
There is evidence of blessing upon the nations that are believed to have been the inhabited by the Lost Ten Tribes. Whether this is a case of finding nations to fit the prophecy or whether this is what is meant by the prophecies is up in the air as far as many people are concerned.
Meanwhile, God laughs at what the nations of the Earth do, as they oppose Him and decry His laws as impotent and unworthy of acknowledgement. Once the nations of the Earth are judged, then the Kingdom of Lord Jesus Christ will reign over the planet (Psalm 2:1-8). This is when all the nations will be blessed for a one thousand year period (Revelation 20:4-6).