President Joseph Fielding Smith (1876–1972) identified the two nations referred to in 2 Nephi 29:7–8:
“This was spoken by prophecy to the gentiles of the present day. It should be remembered also, that the law given to Israel was that ‘the testimony of two men is true,’ providing they are honorable witnesses. Here the Lord applies the law to nations. Why should it not be so?
“If the word of the Lord is to be established by two chosen witnesses, then we may well look for two chosen nations to stand as witnesses for Jesus Christ. One such nation was Israel in Palestine, the other was Israel in America, Judah speaking from the Old World and Joseph from the New. Today these two testimonies for God and his truth have run together” (Doctrines of Salvation, comp. Bruce R. McConkie, 3 vols. [1954–56], 1:278).