Mormon himself later chronicles the destructive power of the Gadianton robbers. During his day, they had reached the pinnacle of their strength. But, like a parasite that kills its host, their wicked strength overcame the righteousness of the Nephites until they could no longer glut themselves upon their labors.
In the words of Mormon, ’the land was filled with robbers and with Lamanites…therefore there was blood and carnage spread throughout all the face of the land…no man could keep that which was his own, for the thieves, and the robbers, and the murderers, and the magic art, and the witchcraft which was in the land…And it is impossible for the tongue to describe, or for man to write a perfect description of the horrible scene of the blood and carnage which was among the people, both of the Nephites and of the Lamanites; and every heart was hardened, so that they delighted in the shedding of blood continually (Mormon 2:8-10; 4:11).’
“Thus we comprehend how Mormon had clearly seen from prophecy and from the social ills of his own lifetime the nature and origin of the destructive forces among the Nephites, and he knows that Satan is the ultimate source. This perspective is later echoed by his son Moroni, who laments that ’they [secret combinations] have caused the destruction of this people of whom I am now speaking [the Jaredite civilization], and also the destruction of the people of Nephi’ (Ether 8:21).” (Book of Mormon Symposium Series, “Helaman – 3 Nephi 8,”edited by PR Cheesman, MS Nyman, and CD Tate, Jr., 1988, p. 145)
“At this point we are assured that, in time, Gadianton‘s gang would prove ’almost the entire destruction of the people of Nephi’ (Helaman 2:13). If ever a story was worth heeding after that announcement, this is one to which we should pay the closest attention—a nation helpless to resist the march of crime!” (The Prophetic Book of Mormon, p. 552)
Ezra Taft Benson
“Our nation will continue to degenerate unless we read and heed the words of the God of this land, Jesus Christ, and quit building up an upholding the secret combinations which the Book of Mormon tells us proved the downfall of both previous American civilizations.” (A Witness and a Warning, p. 6 as taken from Latter-day Commentary on the Book of Mormon compiled by K. Douglas Bassett, p. 371)