I didn't mean Mexican cartels in the US, just cartels in the US in general. I don't buy that it just doesn't show up in the news, if people appeared decapitated or hanging from overpasses in the US I think you would see it mentioned in the news. The corruption and incompetence of Mexican police makes the problem more obvious since the government has to put the army and federal police on the streets to keep some control.

I think maybe in the US the cartels have reached some equilibrium that allows them to operate without so much violence and be discrete enough that they don't get bothered so much by the police.