SAN PABLO, Colombia -- The paramilitary commander calmly but vividly recounted how his men fought and massacred their way into this strategic northern region, for decades a stronghold of rival leftist rebels.
"The people ran frantically, shouting, throwing themselves into rivers," said the mustached officer in green fatigues, his Czech-made AK-47 assault rifle slung on a post that also supported a saddle and a brightly colored hammock. "The guerrillas had confused them, told them we were a bunch of bloodthirsty savages."Gustavo Alarcon, a 12-year veteran of the nationwide rightist militia army known as the United Self-Defense Forces of Colombia, was friendly in the interview at a cattle ranch a two-hour bumpy drive from this town on the muddy Magdalena River. But something weighed on his mind.
Two years after taking this region rich in oil, gold and cocaine, Alarcon is cool to a proposal by President Andres Pastrana that would hand it back to the leftists without so much as a skirmish.
"We are willing to cooperate in the peace process," he said. "But the thing is, we cannot accept handing back to the guerrillas something which does not belong to them and which they have already lost."
Last month, Pastrana announced a plan to turn greater San Pablo and two neighboring counties along Colombia's main river into a guerrilla safe haven and venue for future peace talks.
However, potentially fatal obstacles stand in the way of the initiative, whose start date is still being negotiated.
Pastrana's concession to the leftist National Liberation Army, or ELN, heartened many Colombians hoping for an end to a campaign of bombings and kidnappings that the rebels waged to force Pastrana to the negotiating table.
But the plan has also sparked angry opposition from locals who have become accustomed to -- if not exactly enthralled with -- their rightist occupiers.
People fear reprisals and strong-arm guerrilla rule should the ELN, the country's second-biggest rebel army, come back from the nearby San Lucas mountains.
Thousands of peasants and shopkeepers joined protests in and around the 1,800-square-mile region last week, including rallies, sit-ins at government offices and highway and river blockades.
"We are on the verge of civil war," said Jairo Orozco, an organizer of a new grass-roots protest movement that claims to be independent but supportive of the right-wing paramilitary forces.
Under a scorching sun in San Pablo's town square, Orozco urged people to take up arms if necessary.
Capitalizing upon -- and some say instigating -- the swelling opposition to Pastrana's plan is Carlos Castano, leader of the 7,000-man rightist militia forces and son of a rancher slain by the FARC.
Observers say Castano, known principally as a purveyor of violence, has seized the opportunity to try to build a political following while forging a new image as peacemaker.
Looming darkly in people's minds is a huge demilitarized zone already ceded to Colombia's largest left-wing rebel movement, the Revolutionary Armed Forces of Colombia.
Pastrana evacuated his security forces from a 16,000-square-mile southern ranching area 17 months ago to spur peace talks with the group, known as the FARC.
While those talks move glacially, the FARC is allegedly using the sanctuary to rustle cattle, appropriate land, forcibly recruit teen-age fighters and plunge deeper into the lucrative cocaine trade.
Pastrana has pledged tighter controls in the north, including international observers and naval patrols along the Magdalena River. The ELN has promised better behavior than the FARC.
But there is a big difference between the FARC's sparsely inhabited southern haven and this volatile region in the north where the ELN, FARC and paramilitaries are all active and where a refinery produces 75 percent of Colombia's gasoline.
"It's the bellybutton of Colombia," said Monsignor Jaime Prieto, the Roman Catholic bishop of Barrancabermeja, site of the state-owned refinery and the commercial hub of the region that includes San Pablo, Cantagallo and Yondo.
"Castano gained this territory through war, and now he wants to show that he's politically powerful, too," said the Rev. Francisco D'Roux, a Jesuit peace activist in Barrancabermeja.
Earlier this month, Castano announced he would respect Pastrana's plan if the ELN ceased military actions nationwide during the nine-month trial period the president has proposed. The rebels have not replied.
And many believe Castano's true price for cooperating is a place in the talks for himself -- something the guerrillas oppose and Pastrana has ruled out for the time being.
Meanwhile, Castano's men stand ready to carry out any order he hands down.
"We're willing to support the people to the ultimate consequences," said Alarcon, the regional paramilitary chief, who says he commands several 320-man units. "Our movement is growing every day."