In their book, entitled The Story of Israel, Pate et al. present four arguments as an explanation of the morality of the conquest and the killing of the Canaanites. First, they argue that the destroying of the canaanites only applied to those in the promised land and so was not a command of genocide and ethnic cleansing. The emphasis was primarily on destroying the military combatants in the promised land and driving out the non-combatant canaanites. When an invading army approached the city, this would prompt the women and children and the population at large to flee from harm’s way. This is a different scenario than a complete annihilation of every Canaanite that breathes. Although Joshua 10:40 states, “So Joshua subdued the whole region, including the hill country, the Negev, the western foothills and the mountain slopes, together with all their kings. He left no survivors. He totally destroyed all who breathed, just as the Lord, the God of Israel, had commanded” (NIV), this should be considered exaggerated warfare rhetoric, which was common in the ancient Near East. In fact, a thorough examination of the history, shows that not all the Canaanites were killed or driven out of the land.
The second argument submitted by Pate et al. is that the Canaanite society that was to be destroyed was totally corrupt and immoral. In other words, they had crossed a moral threshold to the point where God intervened with his judgement. Paul Copan writes,
I’m not arguing that the Canaanites were the worst specimens of humanity that ever existed, nor am I arguing that the Canaanites won the immorality contest for the worst behaved peoples in all the the ancient Near East. That said the evidence for the profound moral corruption was abundant. God considered them ripe for divine judgement, which would be carried out in keeping with God’s saving purposes in history.
God’s commands regarding the Canaanites were not arbitrary, and only he could determine when such judgment was required. In the case of the Canaanites, only God understood the depths of their evil and moral corruption, and so he orchestrated his judgement to confront the Canaanites and to protect the Israelites from going down the same path. While God used the Israelites to enact his judgment on the Canaanites, this only came about by divine revelation. Israel was not allowed to go to war with other nations without divine approval. In fact, 1 Samuel 4 describes an incident when the Israelites went into battle with the ark of covenant against the Philistines without God’s approval which resulted in a lopsided defeat by the Philistines. Other disastrous results can be seen at other times in Israel’s history when they go outside the bounds of God’s approval (e.g. Num 14:41-45; Josh 7). God’s call for Israel to go to battle was unique to Israel’s situation, and so a decision for a nation to go to war should not be based on Israel’s battle history.
The next argument is based on Genesis 15:16 which implies that as early as the time of Abraham, the sin and corruption of the Canaanites was an issue. Therefore, God’s judgement on the Canaanites had been delayed to the time of Joshua. This argument is closely related to the previous one in that it is focused on God’s sovereignty, omniscience and timing. According to this argument, the time was not right for judgment and for the driving out of the land. Rather, God with his infinite wisdom waited 430 years to execute his sovereign judgement on the Canaanites. Whereas in the case of the people during Noah’s time (Gen 6:11-13) and in the case of Sodom and Gomorrah (Gen 18-19), God determined that at that time it was right for those people to undergo judgement. Therefore, with this view, judgement on the Canaanites was inevitable, but the Canaanites had hundreds of years to right the ship, which leads to the fourth argument.
The final argument presented by Pate et al. is focused on Rahab and other inhabitants of the land who turn to the one, true God. This argument emphasizes the possibility of the Canaanites turning to God and avoiding his judgement. While Rahab and her family acknowledged God, the Canaanites refused God. Rahab and the Canaanites were not ignorant of God which is evident in Rahab’s statement to the spies,
We have heard how the Lord dried up the water of the Red Sea for you when you came out of Egypt, and what you did to Sihon and Og, the two kings of the Amorites east of the Jordan, whom you completely destroyed. When we heard of it, our hearts melted in fear and everyone’s courage failed because of you, for the Lord your God is God in heaven above and on the earth below (Josh 2:10-11 NIV).
Therefore, with this information the Canaanites could have repented like other nations that were confronted with the knowledge, power and majesty of God (e.g. Nineveh). Copan writes, “Each time the Israelites circled the city [Jericho] meant an opportunity for Jericho to evade the ban; sadly, each opportunity was met with Jericho’s refusal to relent and acknowledge Yahweh’s rule.” Moreover, God reveals himself through conscience, reason and human experience, and he gives to humanity an internal consciousness of what is good and right. The Canaanites, with a basic understanding of right and wrong (i.e. wrong to offer child sacrifices), could have at the very least been capable of moral improvement from generation to generation which may have delivered them from God’s judgment.
 Marvin C. Pate, et al. The Story of Israel: A Biblical Theology, (Downers Grove, IL: InterVarsity, 2004), 55.  Paul Copan, Is God a Moral Monster?: Making Sense of the Old Testament God, (Grand Rapids, MI: Baker, 2011), 181.  Ibid., 170.  Pate et al., The Story, 55.  Copan, Is God, 160.  Ibid., 161.  Pate et al., The Story, 56.  Ibid., 56.  Copan, Is God, 159.  Ibid., 178.  Ibid., 162.