3 Nephi 7:2

And the people were divided one against another; and they did separate one from another, into tribes, every man according to his family, and his kindred and friends; and thus they did destroy the government of the land.

The people were divided against each other. They separated into tribes. Each person went with their family, relatives, and friends. This destroyed the government of the land.

The people turned on each other. They split into tribes, each person siding with their own family, relatives, and close friends. The government collapsed.