Should we take the 汉奸逻辑 to fool ourselves and our children. Did the Americans (according to your logic, they grew in Christianity) showed an mercy to the Jap war criminals?
We fight for justice, not for retaliation. But when the criminals will only learn from punishments, then we must punish them.
Just to remind you that the new Jap prime minister hornored the dead war criminals two-days ago and Japan never officially appologized for the war crimes they committed toward other Asian countries and people.