He said that the municipalities that have seen the most relentless guerrillas attacks, Toribio, Caldono, and Argelia, are places where the army has blocked movement corridors used to shuttle drugs from the center of the country, and the coca-covered mountains, towards the Pacific coast.

The Pacific coast department of Cauca has seen an increase in FARC activity over the last two months. (See InSight’s map of the most recent attacks). Most of these have been attributed to the rebel group’s 6th Front, commanded by alias “Grillo,” which the government says is responsible for running the drug trade through the region.

The government recently announced a security push in Cauca to contain rebel attacks, along with deployments in the neighboring coastal departments of Nariño and Valle del Cauca. In a move dubbed “Operation Troy,” some 1,400 police officers will be deployed to this area, which is one of the parts of the country with the highest presence of illegal armed groups. President Juan Manuel Santos met with senior military commanders in March to discuss further measures, such as placing an army base in the town of Caloto, and building civilian intelligence networks to inform on suspicious activity and anticipate rebel actions.

Despite this military activity, Cauca remains a stronghold for the FARC, and, as InSight has noted, it is one of the last regions where they still have the strrength to mount sustained military operations against the army.

The governor’s comments echoed those of the commander of the army, General Alejandro Navas, who said in March that recent disturbances in Cauca were due to the FARC’s efforts to secure the Pacific drug route. He argued, however, that the guerrillas are not capable of inflicting real damage in combat in Cauca. “The aim is to give an appearance,” he said. “They have the capacity to cause trouble, damage, but not to face the security forces as they did in the last decade.” According to the general, the FARC’s current strategy in the area is to carry out a lot of small-scale attacks to give the impression of greater strength than they in fact have.

The general’s statements do not seem to match the pattern of attacks in the weeks since he spoke. The rebels have managed to inflict a number of casualties on the security forces, and have tried on several occasions to take over entire towns, as with the May 15 attack on Corinto (see map). The army has been unable to contain rebel actions or protect the towns from attacks.

The Cauca area is a very important drug trafficking corridor for the FARC, as the majority of drugs exported from the country now go via the Pacific. According to U.S. government estimates, almost 70 percent of all cocaine entering that country in 2007 came via Colombia’s Pacific coast. It is also an important region for drug production, with significant plantations of both marijuana and coca crops. The most recent United Nations Office of Drugs and Crime illicit crop monitoring report·highlighted Cauca, where it said the area of land under illicit cultivation had increased four-fold between 2004 and 2009, even as it dropped in many other parts of the country. Much of the FARC’s revenue comes from narcotics trafficking, and so protecting drug crops and the trafficking routes is a top priority for the rebel group.

But there may be other motives for the Cauca attacks, aside from protecting drug routes and crops. The northeast area of Cauca, where most of the recent attacks have been clustered, is also a traditional movement corridor for the guerrilla group, in terms of transporting supplies, funds, and troops. Colombian authorities have previously attributed attacks in this area to efforts to keep the supply chain and safe passageways open for the rebels’ top leader “Alfonso Cano” and his security rings.

Another recent cause of conflict in Cauca is clashes between the FARC and emerging criminal groups, known as BACRIM by the government. Drug gang the Rastrojos have their home base in their area, and have been clashing with the rebels over control of territory and drug routes. The two illegal armed groups engaged in heavy combat in February, causing at least 20 casualties in one week. Rival trafficking group the Urabeños are also reportedly moving south from their traditional base on the Caribbean coast, into Valle del Cauca, a department whose border is not far from the site of recent guerrilla attacks in northeast Cauca.

Also present in Cauca are the FARC's old rivals the National Liberation Army (Ejercito de Liberacion Nacional - ELN). Although the two rebel armies have officially agreed to cooperate, tensions remain, and the ELN have made an alliance with the Rastrojos. This would put the groups into indirect competition, especially in Cauca, which is also a stronghold for the ELN.

The FARC’s recent heightened activity in Cauca may therefore be as much a response to incursions and challenges from other illegal armed groups as to government actions.