Among Book of Mormon peoples, military commanders typically corresponded with each other before launching any attacks. For example, in 3 Nephi 3 we find the Gadianton leader, Giddianhi, writing to Lachoneus “desiring that [he] would yield up [his] cities, his lands, and [his] possessions” (3 Nephi 3:6). According to John Welch, this is not surprising because not only ancient custom, but also Israelite law, required parties to justify their conduct and to consider a peaceful resolution before resorting to mayhem. “When thou comest nigh unto a city to fight against it, then proclaim peace unto it. And it shall be, if it make thee answer of peace, and open unto thee, then it shall be, that all the people that is found therein shall be tributaries unto thee, and they shall serve thee.” If this offer were rejected, the Israelites could then besiege the city and totally destroy all its males. (Deuteronomy 20:10-13)
This rule even applied in wars of national survival: “According to the Rabbis, the Biblical command that there must be a prior declaration of war, that a sneak attack like a ‘Pearl Harbor’ was forbidden, applies even to a war of obligation. Even a nation at war must take all possible steps to avoid the shedding of blood… . (see also D & C 98:23-48) [John W. Welch, ”Law and War in the Book of Mormon," in Warfare in the Book of Mormon, F.A.R.M.S., p. 60]