So therefore it is legitimate to blame the US for most (or even all) violence in South America.
For example, the town of Tancítaro became prosperous (and therefore valuable for organized crime) because they grow lots of avocados. The US doesn't fight a war against avocados.
Since they don't know any reputable trades, some problems with protection rackets etc. will remain for years. No one will be perverse enough to blame those echos of The Drug War on the fact that we finally decided to end it. What, did you think that narcos are somehow representative of Mexican national character? They most certainly are not.
Because other than botched ATF stings, I haven't heard any claims of this previously.
For example, one study is at https://nacla.org/article/small-arms-trade-latin-america.
> The U.S.-Mexican border is also a central route through which illicit small arms enter Latin America. A study released by the Mexican government suggests that as many as 2,000 guns are crossing the U.S.-Mexico border daily. As in Colombia, these guns are fueling an arms race, in this case between Mexican drug cartels, costing the lives of 4,000 people in 18 months.14 Weapons, including assault rifles like AK-47s, AR-15s, and M-16s, fetch up to three times their U.S. market value in Mexico, assuring a continued southward flow of weapons.
M16s are only a part of the problem. AR15s and ordinary 9mm handguns can be had in Walmarts or "conveniently" bought without any background checks/documentation on private sales.
I mean, I understand the appeal on having a 9mm at home for self defense, and a hunting rifle for, well, hunting - but having AR15 or worse for everyone at a supermarket? And then the ability to sell 'em on without any record of the transferral? I don't get the US on gun rights sometimes.