The author actually did. He provided support in the paragraphs proceeding and provided a link for further study.
The United States and Great Britain in Bible Prophecy
It's definitely not a salvational issue, but it certainly makes sense in the context of bible prophecy and the ascendancy of the United States and the British Empire.
Thanks—I’ll check per your leading.
Obviously, you referred here to these two paragraphs:
"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 nameprophesied 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. "
Friend, that is no support at all. Instead, it is raw speculation, an unfounded conclusion. The author claims those prophecies were fulfilled but fails to offer any substantiation at all. He merely assumes that which he claims.