Alma invokes Jehovah’s aid, and defeats Amlici. While this might have ended a war with the Amlicites, there was a king of the Lamanites as well. That king retreated and sent guards to battle with Alma, and certainly with Alma’s guards. They are repulsed.
The point, from Mormon’s point of view, is that Jehovah’s hand is evident in the battle. Alma is righteous, and, therefore, is protected against those who would fight against him. Mormon doesn’t specifically invoke the promise of the land, but expects that his readers understand that it is being dramatically fulfilled.