Vicious Cycle

I was very interested in the Charles Bowden interview about the cyclical aspect of the drug killing epidemic/ immigration issue. Is immigration into the U.S. causing perpetuating the drug trafficking that is leading to all these deaths, or are we (the United States government) causing more deaths by preventing Mexicans from escape the drug death culture? Is the United States causing this economic dependence on drug trade in the Mexican economy? How can the deaths due to drug trade be limited when the Mexican economy is so dependent on it? It seems like if one fixes one factor in this crisis (in both Juarez and Mexico in general), another element of the crisis will become worse. Any thoughts?