The third chapter of John Sorenson's new book, Mormon's Codex provides a completely secular view of Nephite history. This is not the first time such a thing has been done. One can look at contributions by John Sorenson and John Welch in the book Warfare in the Book of Mormon and they do the same thing.
This is a remarkable thing as both Sorenson and Welch are believers, not secularists. Secularists do not write secular histories of Nephite civilization, only believers do. On one level this seems counter-intuitive; on another level, perfectly obvious.
It seems counter-intuitive because ancient histories in general are deeply religious. Thus secularists routinely write secular histories of ancient societies that strip away the religious element of ancient histories. Egyptologists routinely write about Egyptian history and discuss such things as Sesostris I raiding Nubia without saying that Osiris commanded it. Assyriologists also write about the conquests of the Sargonid kings without noting that they claimed to conquer by the command of Assur.
The Book of Mormon is different. One has to be a believer in the first place to consider it ancient history. Only when one considers it real history can one write a secular history of the civilization.
One does not have to be a believer to talk about Book of Mormon theology, in fact it is usually easier to talk about Book of Mormon theology when one is not a believer. Theology is a systematic ordering and attempt to derive knowledge of divine things by human reason alone. Believers tend to think that knowledge of divine things need to come by revelation. Originally, theology was lies told about God to manipulate simpletons for political ends. Believers do not engage in such actions but non-believers do.
So non-believers will find it easy to produce Book of Mormon theology, but only a believer will produce Book of Mormon history.