Any economist armed with basic macroeconomic theory could explain how U.S. drug policies create the perverse incentives that have fueled the violence- and how to fix these policies to end the carnage.
Legalizing marijuana in California would be a tremendous step in the right direction. Though it may seem counter-intuitive, economists understand that legalizing marijuana would greatly decrease its value and put an end to the violent drug cartel that currently profits from its sale (and uses those profits to secure future profits by purchasing arms and murdering competitors).
There are huge profits made by many on both sides of the border in drugs. Money laundering, corrupt banks and hedge funds, the prison-industrial complex (with all the building of prisons and the powerful, at least in California, prison guards union, politicians who scream law and order to get elected., why there are many with vested interests in keeping marijuana illegal, even if thousands are dying because of it.