Ironically, a Nephite was more likely to suffer execution at the hands of Moroni than a Lamanite was. Time and time again, Moroni lets the Lamanite prisoners go if they covenant to fight no longer. On the other hand, Moroni considered Nephite traitors a much greater threat than Lamanite soldiers. Accordingly, for the safety of their country, he speedily executed those who remained in defiance. Tragically, the Nephite inner vessel was cleansed by the blood of its own people.
"One might ask, Why compel men to fight or be executed? The answer is simple: treason is a serious offense. Pachus and his men were committed to the overthrow of Nephite freedom. To permit to live men who insisted on using the sword to destroy the very thing Moroni's soldiers were fighting and dying to preserve would be treason to the God-inspired cause of liberty. This neither Moroni nor Pahoran would do." (Book of Mormon Student Manual, 1981, p. 348)