Yep, exactly. The Zetas cartel for example, do not necessarily import & export themselves. They are simply a gang of thugs who move into an area already teeming

Yep, exactly. The Zetas cartel for example, do not necessarily import & export themselves. They are simply a gang of thugs who move into an area already teeming with drug smugglers/dealers, and extort them for taxes. Since these drug dealers can't go to the police for protection since they are doing something illegal they either pay up or the streets turn into a bloodbath. If you notice the Zetas are mainly concentrated in Northern Mexico where the major smuggling routes into the US are. By controlling those they can siphon off 20-30% of all drug shipments from every other cartel into the US and never have to touch drugs themselves, so are unlikely to be caught. They are just parasites off other people's hard work of manufacturing, smuggling and building sales networks. This business model will only work under prohibition. Zetas do not hold up trucks full of tequilla and beer going into the US for extortion because they would be arrested. When your business is legal the solution for dealing with thugs is simple: call the cops or sue them. When you are gray area/illegal your only negotiation is to pay them or pick up a gun creating an all out war.