This war appears to be worse than any previously fought in Nephite history. In particular, Mormon notes that the opposing army of Gadianton-infested Lamanites “did take many prisoners both women and children, and did offer them up as sacrifices unto their idol gods.”
In a Mesoamerican context, this comment fits, but is worth a note. It was not unusual in Mesoamerican warfare to take opposing warriors as prisoners, and to sacrifice them. That was probably happening in many of the wars between Lamanites and Nephites. It was sufficiently common that it was not worth mentioning, a cultural assumption that Mormon didn’t believe it necessary to explain. However, it was necessary to explain that now women and children were being taken as sacrifices.
Mormon appears to be suggesting that warfare is changing, and the cultural rules for acceptable ways to wage war were also shifting. It had not been common to take women and children, but now they were being taken. Even worse, they were sacrificed to foreign gods. It was an unspeakable crime. Mormon’s plausible purpose in relating this goes beyond the need to report history. It was an indication of the shift in the nature of warfare. All of the rules were being destroyed along with civilization.
Although not specifically associated with sacrificing captured women and children, it is notable that Teotihuacan is credited with altering the nature of Mesoamerican warfare and introducing a more deadly aspect than had been previously known.