I saw an interview on the John Ankerberg show. It was a retired general who was very high up, I think a four star one who was in charge of much of the Army.
He said there was clear evidence of Muslim terrorists in Mexico, and in large numbers. He also said a lot of the murders in the last year or so had the fingerprint of Islam rather than drug dealers. Of course the terrorists are involved in the drug trade too.
There is a growing contingent of Hezbollah and al Qaeda support cells setting up shop in the tri-border region of Paraguay, Argentina and Brazil. Venezuela also has regularly scheduled cargo/passenger shuttle flights to/from Iran. The Quds force has a base in Venezuela as well.