The continued kidnappings and drug gang connections have cost the leftist rebels a lot of public support. And this is making it possible more successful army operations against rebels. It's easier to get information from people in the countryside, partly because better trained troops are less likely to behave like invading barbarians. US Special Forces trainers have, for years, worked to convince the army and police that good behavior in the field would gain the support of local people, support that ultimately saves the lives of soldiers and civilians, and provides information on where the rebels, their camps and, increasingly, their kidnap victims are. The US is also providing electronic surveillance equipment that enables troops and police to listen in to rebel communications.
The rebels have, over the last decade, become more oppressive in their treatment of civilians they did not completely trust. Thus the rebels have gone from heroes of the socialist revolution to bandits living off kidnapping and drug gang protection money.