After reading the article, the title makes me question correlation/causation.
"A key problem is that cartels have diversified to a portfolio of other crimes, from sex trafficking to stealing crude oil from Mexican pipelines. They also make billions smuggling hard drugs. Seizures of both heroin and crystal meth on the U.S.-Mexico border have gone up as those of marijuana have sunk..."
EDIT:
The title sounds like it is impacting overall drug traffic, as opposed to simply a shift in the type of traffic.
"A key problem is that cartels have diversified to a portfolio of other crimes, from sex trafficking to stealing crude oil from Mexican pipelines. They also make billions smuggling hard drugs. Seizures of both heroin and crystal meth on the U.S.-Mexico border have gone up as those of marijuana have sunk..."
EDIT: The title sounds like it is impacting overall drug traffic, as opposed to simply a shift in the type of traffic.