Has anybody noticed that, before Christianity, nobody ever dreamed that there were some things you couldn't do to noncombatants and defeated nations. If you conquered in battle, then the people belonged to you to kill, rape, or enslave as you saw fit. What the ban on, say, the Amalekites does is remove the last two options.
As I pointed out in one of the discussions, the just war theory was invented by Christians. Not secular humanists.
I still consider this an insufficient defense of the Amalekite ban. But people who criticize the Bible should recognize where the ideas come from by which they criticize it.
Of course, people like Dawkins help themselves to these moral ideas as if they were somehow obvious, when in fact they were pretty much unheard of before Christians came on the scene.