While Moroni is in the east, the war has not been going well on the western front. The Lamanites on the West have gained some cities in the hegemony of Zarahemla. Mormon attributes these gains to dissensions among the Nephites. Certainly we have seen that the Nephites were prone to dissensions. How is it that these dissensions allowed the Lamanite victories?
The text does not give us the answer, so any answer is speculation. The types of dissensions we have seen among the Nephites all suggest that there were people in the land of Zarahemla who were sympathetic to the political and cultural life of the Lamanites. The kingmen were willing to allow the Lamanites easy access to Nephite territory. It would not be surprising that the dissensions that allowed the Lamanite victories consisted of yet more of the people of the land of Zarahemla expressing their preference for the ways of the Lamanites, and allowing the Lamanite victories by refusing to fight as did the kingmen, or by a more active sabotage of the Nephite defenses.
Geographic: Verse 8 gives us the interesting directional statement that the armies of the Lamanites were “on the west sea, south.” While the reference is somewhat confusing, it appears to indicate the southern section of the land of Zarahemla along the coast of the west sea. (Sorenson uses this interpretation in Sorenson 1990, p. 286. Ludlow 1976 suggests that it is the west sea that is now south because of the northward movement of the Nephites. This is much less likely. The Nephites have not moved that far north, and there is no reason to assume that “south” modifies the “west sea” instead of simply the southern part of the holdings of the greater land of Zarahemla.)