And of course it is the . demand for drugs that fuels Mexican drug smuggling in the first place. Take, for example, the current heroin epidemic in the United States. It originated in the over–prescription of medical opiates to treat pain. The subsequent efforts to reduce the over–prescription of painkillers led those Americans who became dependent on them to resort to illegal heroin. That in turn stimulated a vast expansion of poppy cultivation in Mexico, particularly in Guerrero. In 2015, Mexico’s opium poppy cultivation reached perhaps 28,000 hectares, enough to distill about 70 tons of heroin (which is even more than the 24–50 tons estimated to be necessary to meet the . demand).
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.