The above eight verses are Mormon’s abridgment of six years of the record written upon the plates of Nephi by Nephi, son of Helaman. Under the new chief judge, Nephi, the dissenters were driven out of the land after much bloodshed. As servants of Satan, the Nephite dissenters attempted to stir up the Lamanites to war (vv. 1–3). We assume this contentious period lasted only the first year since Mormon makes no mention of the fifty-fifth year. The Lamanites going to war again is assumed to be caused by their previous defeats by the Nephites, and not from a fear of God. Those Lamanites who feared God were undoubtedly among the tens of thousands that had been converted to the gospel (see Helaman 3:26).
In the fifty-sixth year, other Nephite dissenters joined the pervious group and collectively they were successful in getting the Lamanites to follow Satan’s plan of anger (Helaman 4:4; see 2 Nephi 28:19–20). In three years the Nephites were driven out of the entire land of Zarahemla (Helaman 4:5–6, 8). Thus one of the results of dissensions and contention is the loss of property, a primary responsibility of a government under God (see D&C 134:1–2).
Notice again that the line fortified was from the west sea to the east (v. 7) not the east sea. How much farther it was to the east sea is not given (see Alma 22:32 and commentary on that verse in volume three of this work).