Apparently motivated after some time or after a “last straw” provocation to take decisive action, Noah sends “armies,” which return victorious, “rejoicing in their spoil.” In other words, after “guards” have proved ineffective, Noah sends not just a single “army,” but “armies.” Nor apparently do these armies target the raiders per se, especially if they were marginalized from the main Lamanite society. I hypothesize that Noah’s armies, like Zeniff’s, attacked Lamanite settlements. The fact that they return with “spoil” rather than the stolen flocks and crops suggests reprisal, rather than recovery. As such, this counterattack fits the model of Mesoamerican warfare, with its economic benefit of despoiling a conquered people. Noah avenges attacks on his farmers and herders with attacks on unspecified targets (but probably villages).
From the Lamanite perspective, such an attack is a decisively negative step in Lamanite-Noahite relationships. If the Lamanite raiders had been marauders acting outside Lamanite authority, then Noah’s reprisal against what, in Lamanite terms, would be innocent civilians would justify a punitive Lamanite response. While there is no direct evidence to support such a scenario, the alternative view is that the Lamanites perpetually engaged in warfare against the Nephites because they were evil and hate-filled. That explanation seems too simplistic.