Parents who appropriately punish their children are doing G-d’s work and are rewarded for their expressions of love and caring. However, the “punishing nations” have never accepted their position as the extended hand of a loving G-d chastising and punishing His chosen people. Therefore, they will be punished, rather than rewarded.
The imagery is intended to focus us on the emotional and unbreakable bond that exists between us and Hashem. It is no different than a mother who must cope with the child who ignores and disobeys her. However, in spite of the hurt and the responsibility to punish, the parent is incapable of separating herself from the love and concern she feels for her child, even more so at the time of punishment! It is therefore incumbent upon the child, not the mother, to recognize the parents’ ever present love, and embrace, rather than shun, the relationship.
In the end, recognizing that Hashem has never and will never abandoned us, especially at the times of our greatest trials and tragedies, will reawaken our love for Hashem and bring comfort to the nation and Eretz Yisroel.