If you legalize drugs in Mexico though and they can start legitimate companies that might end the violence, but would be a huge blow to the rule of law.
I disagree with your perceived loss of justice should drug use be legalized. Laws exist to protect people. Drug laws have only served to hurt nearly every person on earth when considering supply chain and tangential effects. By opening up the law to allow people to self medicate we are actually reducing harm at every step from the companies producing raw materials to the end users. To only consider a solution that outlaws the existence of an addict is inhumane, immoral, impossible, and outright delusional. To learn more about these topics and hopefully gain some empathy for addicts I suggest reading Gabor Matès "In the realm of hungry ghosts."
https://barnesandnoble.com/w/in-the-realm-of-hungry-ghosts-g...
If the cartels are allowed to operate legally, I'm worried about them having committed crimes for decades and being rewarded with first moved advantage into the new market. I think that would be a slap in the face to the rule of law. I'm not worried about the consumer as typically people should be able to self medicate and experiment as you suggest.
If you're a meth producer that killed (suspected) competitors and snitches, you're in for a lot of problems if you want to make your business legal.
"Oh, hi. I'd like to register a new LLC, these are my papers..."
I’m not sure you’ve run the numbers on this. In 2016 there was 11k gun homicides in the US, and about 64k people died from opioid overdoses alone. I can’t really see an insentive here for the US.
Anyway I don't think people calling for legalisation are suggesting heroin should be handed out to school kids at break time. You can legalise it and setup strict regulations around it as well as redirect money spent on enforcement to health and prevention.
It would be interesting (and a welcome outcome) to see if this insight and method of fighting crime is accepted and used by locales high relative violence rates.
Lauren Southern receives $68,000 bill from Victoria Police
https://www.heraldsun.com.au/blogs/andrew-bolt/lauren-southe...
https://www.heraldsun.com.au/blogs/andrew-bolt/lauren-southe...
Until the police/military are strong and law abiding enough, cartels will continue to see violence as a risk worth taking even if their main business becomes legal.