The original attack on the Anti-Nephi-Lehies may be ascribed to the overthrow of the government and the seating of the new king. Because that had already happened, perhaps the Anti-Nephi-Lehies felt that any great threat was behind them. This more recent attack proved that they were in grave danger. Therefore, Ammon and his brothers believe that their only salvation was to leave the land. They had already become a different type of people from the Lamanites, believing more like their enemy, the Nephites. Now they were to become Nephites not only in belief, but in land and political affiliation.
The king, Anti-Nephi-Lehi, is fearful because all understood that there was hatred on both sides of the Lamanite-Nephite divide. He would correctly fear that “the Nephites will destroy us.” It is the reverse of the fear that Ammon and his brothers would have had as they entered Lamanite lands.
Ammon asks if they will go to Zarahemla if the Lord tells them to. For a people who were willing to lay down their lives for the covenants that they had made to follow God, that would have been an easy answer. Of course, they would go.