Because it was a land of promise for the Jaredites and Nephites, it becomes a land of promise to all potential inhabitants. The land’s inherent promise can become a potential covenant for all who live on it. The blessing will apply to “whatsoever nation shall possess it,” but so does the penalty: If a nation turns from God, it will be “swept away.” This isn’t a Jaredite promise or a Nephite promise. It is God’s promise to any people willing to enter into the covenant.
Why is the New World a promised land and the Old World is not? That is the wrong question. Israel’s promised land was in the Old World, so God does not have a hemispheric preference. Historically Israel considered its promised land to be a fixed location, separate from any other possible location. The Book of Mormon continues the idea of a promised land, but the land is less important than the people living on it. Perhaps the Book of Mormon preserves an older and more accurate version of God’s gift of a promised land to the house of Israel. Perhaps the promise will be in force anywhere in the world that people keep the covenant. The modern world creates societies within societies, seldom allowing an isolated “land” in which religion may be practiced without any outside influences. Nevertheless, there is still a promise attached to righteousness. Wherever the modern Saints find themselves, it is for them a promised land.
Redaction: At this point, Moroni clearly intrudes into the text (vv. 9–13).