I see, but what you fail to understand is that those nations that God had annihilated were EVIL. They were violent, child-sacrificing pagans that spat in God's face even though He continued showing them that He loved them (i.e. giving them plentiful land, bountiful harvests, to say nothing of the other countless blessings on the individual people). Finally, God said: "you have disobeyed my laws and refused to acknowledge me. though I loved you, you hated me. these are the consequences." God still loved them, but they refused to show Him even the slightest hint of love. Why should He continue pouring out His blessings on wretched nations when they turn their backs on Him?