Matthew Roper notes that Jerusalem at the time of Lehi was more than just a city. Babylonian documents refer to Jerusalem as "the city of Judah," representing everything under the control of the king. Even the book of Jeremiah describes the siege of Jerusalem as a time when Nebuchadnezzar's armies fought "against Jerusalem, and against all its cities" (Jeremiah 34:1, New American Standard Bible). Since Jerusalem was the royal and national capital of Judah "all its [Jerusalem's] cities" clearly means all those cities under the national government of Jerusalem, i.e., all the cities of Judah (Jeremiah 34:7). Even if we are more conservative and interpret the phrase "all its cities" as referring only to the Jerusalem district, this would still take in Bethlehem, which was under Jerusalem's jurisdiction. It also needs to be remembered that the term "Jerusalem" is sometimes also used as a general name for the whole southern kingdom (2 Kings 21:13; Isaiah 10:10-11, Ezekiel 23;4; Micah 1:1,5), just as Samaria is a national designation for Israel in the north (1 Kings 13:32; 2 Kings 17:24, 26; 23:19; Ezra 4:16). So whether Alma was using the term "Jerusalem" as a national designation for the kingdom of Judah or only the Jerusalem district, he is correct on both counts. [Matthew Roper, Book Review in Review of Books on the Book of Mormon, Vol. 4 1992, pp. 88-89]
“He Shall Be Born of Mary at Jerusalem”
Book of Mormon critics point to Alma 7:10, "He [Christ] shall be born of Mary, at Jerusalem which is the land of our forefathers" as an anachronism. It is obvious to any Bible reader that Christ was born in Bethlehem (Matthew 2:1; Luke 2:4-7). However, according to John Tvedtnes, there is evidence that in the Old World, Bethlehem was considered to be part of the "land of Jerusalem." One of the Amarna texts speaks of "a town in the land of Jerusalem" named Bit-Ninib. Some scholars give the name as Bit-Lahmi, which is the Canaanite equivalent of the Hebrew name rendered Beth-lehem in English Bibles. Thus, we can conclude that Lehi's descendants in the New World followed authentic Old World custom in denominating each land by the principal city in the land. . . . To the Nephites, whose society revolved around cities controlling larger lands, it would have been perfectly logical to place Bethlehem in the land of Jerusalem. (Bethlehem is only about six miles from the city of Jerusalem) [John A. Tvedtnes, "Cities and Lands in the Book of Mormon," in Journal of Book of Mormon Studies, Fall 1995, F.A.R.M.S., p. 150] [See also Hugh Nibley, An Approach to the Book of Mormon, pp. 85-86]
According to an article by Robert Smith, the "land" or district of Jerusalem was administratively distinguished from the city of Jerusalem. Indeed, the land of Jerusalem extended far beyond mere district borders during its phase as a Latin kingdom, covering about 500 to 550 square kilometers. Thus it is quite apparent that Jerusalem "did double duty as the royal and the district capital." As early as Canaanite times, Jerusalem held royal status, and it was termed mat URU sa-lim ("land of Jerusalem") in the Amarna Letters.
Where then was Jesus born? Truly, in Bethlehem of the land of Judaea (see Micah 5:2; Matthew 2:1-6; Luke 2:4) -- any child could tell you that in Joseph Smith's time as well as in ours. What no one in modern times would have known for sure (before the 1887 discovery of the Tell El-Armarna Tablets) was that Bethlehem was also part of an area anciently called the land of Jerusalem.
Only once in the King James Bible is the term land of Jerusalem even remotely recognizable (2 Samuel 5:6), yet the Book of Mormon twice refers to a "land of Jerusalem" in which Jesus was to be born (Alma 7:10; Helaman 16:19). It is apparent now that the Book of Mormon's casual statements about the "land of Jerusalem" are in full agreement with what recent scholarship tells us about the geography of ancient Judaea. [Robert F. Smith, "The Land of Jerusalem: The Place of Jesus' Birth," in Reexploring the Book of Mormon, pp. 170-171] [See the commentary on 1 Nephi 10:10]