U.S & Mexico's Drug Cartels: Part of the problem or part of the solution?

We all know that the voracious appetite of U.S. residents for illegal drugs is the main reasons why the cartels in Mexico are so powerful. Don't these druggies feel some guilt about all the innocent people and honest cops and military personnel in Mexico who are murdered by cartels? Who are these moral idiots who feel their drug habit is more important than the lives of innocent Mexicans? In addition to inexcusably providing weapons (via BATF), DEA has helped launder millions of dollars in cartel money. Looks to me like the U.S. is part of the problem, not part of the solution. Are some of our federal law enforcement agencies out of control? Arguably, some, including BATF have been out of control for decades (e.g. see Kopel and Blackman, "No More Wacos." Of course don't forget Ruby Ridge.