Although Mormon makes it clear that Morianton’s presence in this northern region would be strategically dangerous for the Nephites, the actual cause of the danger is less clear. Probably the most important reason has to do with the fact of the defection itself. Their demonstrated willingness to attack other members of the Zarahemla polity proves the tenuousness of their allegiance. They are potential dissidents. For reasons not clear to us, their destination was apparently important in defending Nephite territory. Moroni found intolerable the possibility of hostile dissidents holding this territory.
A second suggestion is Mormon’s declaration that “they would hearken to the words of Morianton and unite with his people.” He does not explain who “they” were. Details in verse 29 suggests that Morianton was heading toward the land of Desolation, the ancient Jaredite territory (“the land which was northward, which was covered with large bodies of water”), and take possession. While we assume that the land was empty because of the Jaredite civilization’s destruction, it is highly unlikely that the land was uninhabited. Indeed, archaeological evidence confirms a continuing population.
Their presence suggests that Desolation’s inhabitants were not hostile to the Nephites, as no attacks have originated from the north, but they were probably the people whom Moroni feared would “hearken to the words of Morianton.” If Morianton could mobilize this previously peaceful people against the Nephites, then the danger to Nephite cities was grave indeed. Moroni would certainly be alert to dissidents moving in with potential allies, since his most recent opponent, Amalickiah, was precisely such a dissident who had gained control of the Lamanite lands and armies.
Redaction: This verse gives us an example of a correction inserted into the text. The sentence begins by having the people in Bountiful afraid of the actions of Morianton, while the inserted correction identifies the fear as Moroni’s rather than the people’s. As with other examples of inserted corrections, the source is not clear. Mormon may have began writing, then had to correct the statement within the same sentence because of the impossibility of erasing on metal plates. Or Joseph Smith could have been dictating the text and let his words run ahead of the thought at this point, necessitating the correction.