The Arizona Republic has a good report here about Mexican drug cartels recruiting Guatemalans as foot soldiers. (Even, at one point, raiding an immigration facility to free some minions who had been captured, the newspaper reports.) A lot of the attention has been focused on the drug war's impact on northern Mexico, the border regions, but the cartels also affect Guatemala and other Central American countries, too.
The Republic includes some background on why Mexico has gained more importance in the "drug economy."
Until the early 2000s, Colombian producers moved most of their cocaine through the Caribbean, and they controlled the entire route. But better aerial radar and an increased naval presence have forced drug shipments to go through Central America and Mexico.
That has increased the importance of the Mexican cartels, Cárdenas said. They are now moving quickly to take over the entire route, co-opting Central American gang members and using them as foot soldiers for the Mexican drug lords.