Mormon concludes the story. There is another battle and Lamanites are driven out of the land. Contrast these few details with the previous war. The difference is that there was an important lesson in the defection of the Amlicites. This was just another war. There were no lessons Mormon cared to pull from it, so he reports it succinctly. As noted, Mormon is ironically uninterested in war. He is interested in the people and the lessons to be learned from the conflicts.
Mormon notes that they again “began to establish peace in the land.” As typical, this statement is simply a prelude to the next time that things go wrong.