The traffickers are evil and dangerous, but they are not irrational. They have heard that the U.S. has declared war on them. The U.S. government has imprisoned 80,000 people for drug offenses. In U.S. prisons are 20,000 Mexicans, mostly for drug or immigration crimes, and 4,300 Colombians. The states have jailed tens of thousands more.
Mass graves are merely a new twist to an old story.
Bringing the drug trade under the controls of regulation, licensing and taxation will shrink violence and criminal profits and lead to more effective drug abuse control. Feel free to e-mail an article of interest.