Once formed, enemy images tend to resist change, and serve to perpetuate and intensify the conflict. Because the adversary has come to be viewed as a "diabolical enemy," the conflict is framed as a war between good and evil. Once the parties have framed the conflict in this way, their positions become more rigid. In some cases, zero-sum thinking develops as parties come to believe that they must either secure their own victory, or face defeat. New goals to punish or destroy the opponent arise, and in some cases more militant leadership comes into power.