Mormon makes certain that his reader understands that Moroni had been given authority to make the decisions that he does in this case. Similar to the ending of the battle with Zerahemnah’s army (told in Chapter 43), Moroni gives the captured Amalickiahites the choice to covenant to “support the cause of freedom” or to be put to death. The power of the oath was sufficient that there “were but few who denied the covenant of freedom.” That there were few is not surprising. That there were any who chose death over the oath is even more surprising.
This part of the story ends with the title of liberty being raised over all the land, with the land again having peace. The story began in the beginning of the nineteenth year. They obtained “peace in the land until nearly the end of the nineteenth year of the reign of the judges.” In other words, it lasted only a few months.