Yes, from what I understand most of the beginning of mexicos drug trade came from influence from the DEA but I don't know the specifics on that. I know that alot of the cocaine and some other stuff that comes up through the mexican border also comes up from brazil especially around rio de janeiro.
Fucked up funny story short. I have a mexican cheif mate on here and we saw two different parachute drops coming out of the sky into the ocean outside of rio. One funny american chief mate I got saw one the first time and was all, "whelp, that looks like a crate of dope with a parachute on the top". Which it pretty much was and I think we saw a few "fishing boats" headed in that direction. And the second the mexican mate saw on the bridge and he thought was a ditched pilot falling into the ocean "he's a little naive sometimes". He called it in over the radio to a cruise ship nearby and they kept going after half-assed answering him and I told him it looked like another crate and he said "you're prolly right" and that was it.
But back to the main point. The cartel's traditional source of income is drug trade. But the DEA has been attempting to hammer their drug trade efforts atleast on the border side and their own govt has been trying to snuff out some of it although its about to the same effectiveness of the CDC trying to stop ebola right now. The cartel like I said is embedded deeply into mexican govt and business. Its actually run like a corporation now although as far as I know there are five different divisions of it and they very as far as operation and success. They actually combat each other alot too.
The main cartel, the one that is operated like a corporation is actually doing half-assed legitimate business such as exporting metal ores and like I said petroleum but they're treating their labor like slaves basically as well. They've also been doing alot of human trafficking and I think weapons trade too but I'm not sure on that one. Alot of the weaponry used by the cartel is old US military equipment they buy off of us I'm pretty damn sure. I've seen a defunct navy warship painted with federali name and ect all over it roaming around the oil field once and alot of the "militia" personel I've seen that do security when we come to and from mexico are using what looked like older M-16s and almost mixed style fatigues. Dudes looked like mafia, scars across their eyes, looked fucking jaded and pissed off like they'd done some pretty horrible shit. When they operate around the parts of mexico I've been the guys are riding around in a modified bigass diesel truck. I guess the best type of term I can use is a sort of capitalism gone rampant irony.