In commanding complete destruction of the Canaanites, the Lord says, 'You shall not intermarry with them, giving your daughters to their sons, or taking their daughters for your sons, for they would turn away your sons from following me, to serve other gods' (Deut 7.3-4). […] God knew that if these Canaanite children were allowed to live, they would spell the undoing of Israel. […] Moreover, if we believe, as I do, that God's grace is extended to those who die in infancy or as small children, the death of these children was actually their salvation. We are so wedded to an earthly, naturalistic perspective that we forget that those who die are happy to quit this earth for heaven's incomparable joy. Therefore, God does these children no wrong in taking their lives.
So whom does God wrong in commanding the destruction of the Canaanites? Not the Canaanite adults, for they were corrupt and deserving of judgment. Not the children, for they inherit eternal life. So who is wronged? Ironically, I think the most difficult part of this whole debate is the apparent wrong done to the Israeli soldiers themselves. Can you imagine what it would be like to have to break into some house and kill a terrified woman and her children? The brutalising effect on these Israeli soldiers is disturbing.