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.
This may be true in his corner of the world, the Chinese has been promoting winning without war. When an inevitable war was fight and won, the winning side should not kill or hurt the people conquered. [The Art of War, Sun Zi, 2nd century BC] This idea originated from Confucius and Lao Zi 4th century BC.
Advocating genocide, in any measure at any time and place, is barbaric and the bible has plenty such examples. No wonder when the Christian discovered new world, the indigenous were mass murdered. The few remaining indigenous people Australia and America are examples. In Africa, they capture the black as slaves.