We know from Scripture that the birthright was given to Joseph, then to Ephraim & Manassah. We know from Scripture and history that their descendants never received that birthright; they were merely the largest tribes in a relatively small nation and never had the vast material wealth described in the birthright promise. And we know this promise is from GOD, and that Scripture cannot be broken. And we know from many signs that the return of Christ should be near. It seems that the birthright should be bestowed before His return, and I cannot think of any other candidates besides GB & the USA. We must remember that a birthright is just that; it's bestowed because of birth, and NOT because the recipient is deserving. A famous example...Paris Hilton. She received a fortune because she's a Hilton and her family is rich. It was hers because she was born of a Hilton, before she could do anything right or wrong. Thus it is with GOD'S birthright. Its recipients have or shall receive it because of God's promise to Abraham. We know from the histories of GB & the USA that our nations are not deserving of their wealth. Another Abraham named Lincoln reminded us if that.
But nowhere does Scripture say God will CONTINUE that blessing unless its recipients are true to Him. England has lost its empire. The USA, while still the mightiest one nation, is no longer the dominant world power it once was. However, I believe we still have the most Christians, true churches, and true pastors per capita than does any other nation, and because of this, the USA hasn't degenerated completely.
Consider this Scripture: 2 Samuel 7:10 Moreover I will appoint a place for My people Israel, and will plant them, that they may dwell in a place of their own and move no more; nor shall the sons of wickedness oppress them anymore, as previously,
At that time, Israel was as secure as it ever would be, from its evil neighbors. Yet, God says He WILL appoint them a place to live. (He had already appointed Canaan for them, & they were living there at the time, ALREADY planted there by God.
Modern England was miraculously delivered from her enemies four times...from Spain in 1588, Napoleon in 1805-12, the Kaiser in 1914-18, and, deadliest of all, Hitler in 1940-45. None of these enemies set foot in England, but the British will acknowledge that if any of these enemies had been able to land an army onto the British Isles, they woulda won. As for the USA, the only significant enemy to set foot in her was England, and the English army was given its worst defeat in its history until that time at New Orleans.(Her worst defeats till then had been at {1.}Yorktown & {2.}Saratoga.) Was this all by chance? Of all these enemies, Hitler stood the best chance by far to conquer England. It took an incredible series of blunders for him to have lost. He coulda occupied Dunkirk, then turned the panzers against the BEF, trapping it between two of his armies, thus forcing its surrender. That woulda been a tremendous blow to British morale, and they mighta replaced Churchill with a PM more open to a negotiated peace. He coulda delayed his attack against Russia until England was completely outta the picture, and even w/o delaying that, he coulda not attacked Yugoslavia and Greece; it was this attack which threw off his timetable just enough so that he couldn't defeat Russia because of the Russian winter beginning, a winter for which his forces simply weren't equipped. In the "Battle of Britain", Goering's forces far outnumbered the RAF, and Goering had selected the correct targets, the British radar stations and the sector airfields which coordinated the RAF's responses to German attacks. GB was losing its ability to concentrate the RAF where it could be most effective, as well as her supply of fighter planes and good pilots. Once the RAF was defeared, the Luftwaffe coulda cleared the English Channed of British ships, thus opening the way for a massive invasion. Hitler coulda easily given Rommel enough of a force to have made short work of North Africa and Malta, thus cutting off all British supplies from the Suez Canal & the Mediterranean Sea in general, which woulda soon placed GB in dire straits.
Those are just a few of the things that, with a few tweaks of history, woulda made England entirely different from the England of now. I firmly, 100% believe the HAND OF GOD saved England from her enemies, same as He saved ancient Israel from hers.
Why God has chosen to thus save England, allowing that small nation to acquire, at one time, the world's greatest empire, I leave for others to guess at. I have presented my best guess, based upon Scripture and physical evidence, but as I've often said, I am open to other reasons and other nations besides modern Judah being God's peculiar nations.