If God is fair in all his judgments of mankind, we should be able to see that his judgment upon the Canaanites was fair. It is not enough to say that God owned the land and had the right to evict the Canaanites and give their land to Israel. Of course, as Creator, he had the right to do so, but this does not make what he did fair judgment or moral. The people who were displaced had as much ‘right’ to exist and be where they were as the Israelites did, if we take only an initial and cursory reading of the text into consideration. It is only when we really consider context that we see the issue is much more complex. While it may be a recognized truism that “all is fair in love and war” or “to the victor belong the spoils”, this doesn’t make what was done good, moral behavior. How should we address these things?
What kind of history do the Canaanites have with God’s people? Do we have any indication that Abraham and / or his descendants were mistreated by the inhabitants of the land? I think there is, but we need to remember that in Abraham’s day, the evil of the Canaanites/Amorites was not evil enough to warrant expulsion (Genesis 12:6; 15:16). In fact, we are told that Abraham was in league with the Amorites (Genesis 14:13), something Israel under Moses and Joshua were not permitted to do (Deuteronomy 7:2). Therefore, it seems that their evil gradually increased over a period of 400 to 500 years, and this caused the land to vomit them out (Leviticus 18:28).
Notice that in Genesis 13:7 it is repeated that the Canaanites were dwelling in the land with Abram (cf. Genesis 12:6), but this time it is placed with the quarrel between Abram and his nephew, Lot. While implying the quarrel was instigated by the Canaanites is not proof of the same, it is an odd placement with the event of the quarrel. Were the Canaanites suspicious or jealous of the prosperity / power of Abraham coming out of Egypt? On the other hand and sometime later, one of the princes of the Hivites, a tribe of the Canaanites, defiled Dinah, Jacob’s daughter (Genesis 34:1-7), which may have originally been intended to make Jacob and the Hivites one people (Genesis 34:8-10), which would have erased the uniqueness of Abraham’s descendants (cf. Genesis 17:10-14).
An interesting observation has been made by some Biblical scholars and archaeologists in that, during the time of Israel’s sojourn in Egypt (cir. 1800 to 1400 BC), Egypt fell to the rule of a foreign dynasty, the Hyksos, sometimes referred to the Shepherd Kings:
“Their name (Hyksos) corresponds to the Egyptian ‘rulers of foreign lands,’ but was also understood to mean ‘shepherd kings.’ They were probably preponderantly Semitic Amorites/Canaanites.”
If Jacob and his family went down into Egypt, while Joseph was Prime Minister under Pharaoh, and were treated very well, then it seems the trouble they incurred afterward under the “king who didn’t know Joseph” may have had something to do with these foreign rulers. If the Hyksos didn’t initiate Israel’s troubles in Egypt, they certainly prolonged it, and perhaps furthered it along, through organized infanticide in efforts to control Israel’s growing numbers (Exodus 1:8-16). But, notice, as well that the kings who did this thing wished to destroy Israel’s nationality by destroying all the males, but not the women (Exodus 1:16). Eventually (one might conclude), the women could be assimilated into the Egyptian population, or even die out through attrition, without having males to create families and increase in numbers.
Immediately after Israel left Egypt, the Amorite kings, Sihon of Heshbon and Og of Bashan, came out against Israel in unprovoked attacks (Numbers 21:21-23, 33). All Moses wished to do was pass through their lands by way of the international ‘Kings Highway’, but he was refused and then attacked. The Amorites / Canaanites had shown themselves not only unfriendly toward Israel, but oppressive and sought to destroy their national identity, while they were slaves and in a weak social condition in Egypt. In expelling the Canaanites from the land, God was not only establishing his right to do so as Creator (Genesis 1-2), but also his moral responsibility to do so as Judge of mankind (Genesis 18:25).
 Jack Finegan, Myth and Mystery: An Introduction to the Pagan Religions of the Biblical World (Baker: 1989) 123.