Chris Wright has a very fine chapter on the issue of the extermination of the Cannanites in his book The God I Don't Understand. In chapter 4 he details various inadequate explanations for the command of God for Israel to slaughter the Canaanites. Then in chapter 5 he gives 3 frameworks for understanding what God was doing in that horrific command.
He firstly notes that it appears within the framework of the Old Testament as a whole, and as such we need to keep the following in mind: the culture and rhetoric of ancient warfare, the possibility of God accomodating himself to the fallen reality of warfare at that time and the conquest of Canaan as a unique and limted event. His points are valid and helpful and worthy of ongoing reflection.
The second framework is that of God's sovereign justice - under which he refers to the wickedness of Canaanite culture and religion, the fact that the conquest did not mean Israel was righteous and then, lastly, that God threatened to do the same to Israel and did, in fact, do so. All of this is, again, helpful and proportioning.
His third framework is to situate the conquest within the framework of God's plan of salvation. Here we are treated to material that is not just helpful for the issue at hand but stimulating for a whole approach to grappling with scripture. He notes the Bible's vision of peace, the blessing of the nations, care for foreigners in Old Testament law and, finally, the praise of the nations to Yahweh. The conquest of Canaan has to be seen as one step along the road that leads to Calvary and to the blessing of all nations by the one true God of all the earth.
Wright correctly notes that he isn't giving a definitive answer to the problem of the conquest of Canaan and its apparent brutality. But his way of handling the issue is a model in sustained biblical reflection that leads to a maturing gladness in the God whose character is revealed in scripture and history.
