Peace At Any Price.

Carlos Castano was 16 when Marxist guerrillas kidnapped and murdered his father in the humid hinterlands of Antioquia province in central Colombia. The right-wing paramilitary supremo has spent most of the ensuing two decades cutting a murderous swath through countless towns and villages in a crusade to avenge his father's death. One of the worst atrocities attributed to Castano's Self-Defense Forces of Colombia (AUC) occurred in the southern town of Mapiripan, where 30 suspected leftist sympathizers were rounded up, tortured and slaughtered by his foot soldiers in July 1997. In an interview that year the renegade was unrepentant: "I am not at all sorry for Mapiripan because there wasn't a single innocent among those who died," he thundered. "The type of people who were killed shouldn't worry anyone. I will never regret that." Last June Castano was sentenced in absentia to 40 years in prison for the massacre.

Now the 39-year-old warlord known to many Colombians as the Monster is suing for peace. On July 15, Castano reached a tentative agreement with the government of President Alvaro Uribe to begin disarming his estimated 13,000 combatants later this year. In exchange for giving up their guns, Castano and other paramilitary commanders would be granted a general amnesty for human-rights abuses and other crimes. Peace Commissioner Luis Carlos Restrepo has said that the paramilitary leaders might avoid prison by making cash reparations for their crimes, and that AUC members could make "symbolic acts of contrition" such as public service. (Castano has hinted that they might give back some of the land they seized.) That has officials in both the United States and Colombia crying foul. "People like Carlos Castano, [AUC military chief] Salvatore Mancuso and others who've ordered or committed heinous crimes must be brought to justice," says U.S. Sen. Patrick Leahy of Vermont. "There should be no deals that allow murderers to escape punishment."

Allowing Castano & Co. to walk free could also send the wrong message in the U.S.- financed war on drugs in Colombia. Washington has invested $2.5 billion in Bogota's Plan Colombia anti-drug initiative over the past three years--and the program is starting to yield some results. Uribe claimed last week that aerial spraying had reduced coca cultivation by 15 percent since he took office. Colombia remains the world's leading producer and distributor of cocaine--and by his own admission Castano and some of his top associates turned to drug trafficking sometime ago to help finance their military operations. The Bush administration formally sought the extradition of both Castano and Mancuso last year on charges that they had shipped 17 tons of cocaine to the United States and Europe over a five-year span dating back to 1997.

But Castano now claims he's a changed man. He wants to join the war on drugs--and to prove his newfound commitment, Castano says he wants U.S. officials to attend the next round of peace talks with the Uribe government. "We want to let them know that they can count on our legitimized movement to cooperate in the struggle against drug trafficking," the paramilitary leader told NEWSWEEK by e-mail last week. "We could begin to eradicate thousands of hectares of coca [fields] and expose the drug-trafficking activities that we identify in our regions."

The Bush administration has reacted cautiously to the peace initiative. Two years ago the State Department added the AUC to its list of terrorist organizations, and Washington has publicly refused to negotiate with Colombia's paramilitary forces. A U.S. official last week reiterated that policy. But that position has been called into question by a meeting last May between an AUC representative and a U.S. diplomat in Colombia. According to a leaked memo written by the AUC representative, the diplomat, identified as U.S. Embassy Political Officer Alexander Lee, told the AUC emissary that paramilitary leaders might "receive leniency if they cooperate once in custody."

According to that same memo, the U.S. diplomat supposedly stated that peace talks between the AUC and the ...