Mexico-U.S. cooperation in running counter-drug operations has increased over the last 18 months. The US Drug Enforcement Administration (DEA) has been providing intelligence to Mexican police and other security forces, including the Mexican Navy's elite marine commandos. The Mexican marines have carried out several very high profile (and successful raids), beginning in 2009. The strikes often target drug cartel leaders and senior drug cartel enforcers (hit men).There's more on this at the link.
Critics are arguing that the DEA is going around Mexican police because the U.S. is concerned about corruption in the police forces. That is very true, but the conspiracy theorists seem to ignore the fact that just about every other day the Mexican government points out that it is concerned about police corruption. Unreliable or corrupt police forces is one reason it began using military forces – the other reason being the drug cartels have more firepower than local and state cops.
Several of the more spectacular Mexican marine operations in northwestern Mexico are special operations raids, both strike raids and snatch (arrest) raids. The marines treat the cartelistas as an insurgent force and the cartel leaders as insurgent commanders.
The drug cartels are waging a low-level civil war in Mexico and elsewhere in Central and South America. Hopefully, the combination of highly trained combat forces and American intelligence-gathering capabilities will make their business more risky and less profitable than it has been up till now.