Also included under the topic of killing are the wars of the Lord (20:1–20). Israel differs widely from her neighbors in that she is never allowed to expand her territories by conquest of surrounding nations, for going into battle is solely the Lord’s decision. Israel has no need to prove her greatness by her military strength, power, or possessions, for her greatness is to be found in who her Lord is. Her wars are not “holy wars” but “Yahweh wars” (20:1–4). She has nothing to prove by conquering others.
Rather than chapter 20 being a militaristic chapter, it comes off as being antimilitaristic, as it calls for …
Baker Publishing Group, The Baker Illustrated Bible Commentary, by Gary M. Burge