By JUAN FORERO
 
SANTAFÉ DE RALITO, Colombia - The disappearance and possible murder of Carlos Castaño, the longtime leader of Colombia's right-wing paramilitary forces, have increased the bargaining power of the paramilitaries in disarmament negotiations with the government, Western diplomats and human rights officials said in a series of interviews.

The talks, considered a cornerstone of President Álvaro Uribe's plan to pacify Colombia, stalled after the disappearance of Mr. Castaño. To get them moving again, the government in early May granted 10 paramilitary commanders a 142-square-mile safe haven where they could resume negotiations free from threat of arrest or extradition to the United States on drug-trafficking charges.

But Western diplomats and political analysts questioned the wisdom of embarking on talks with the fierce drug-trafficking militias, which were formed in the early 1980's to fight Marxist rebels. "These are some of the biggest, most ruthless drug dealers in the world, period," a Western diplomat said in early May. "They are essentially negotiating with much more organized, much more dangerous Pablo Escobars," the diplomat said, referring to the late cocaine kingpin. "Because these guys actually have some clout, and much more organizational skills than the rebels, they are deadly."

Indeed, some commanders of the group, a loose coalition of paramilitary factions calling itself the United Self-Defense Forces of Colombia, had discussed in April the assassination of Mr. Uribe as a way of gaining leverage in the negotiations, the president said in an address.

Critics of the government's bargaining strategy say the paramilitary commanders have no intention of changing their ways. "The leaders of these groups are under the impression that they can keep pressing the state for additional concessions to ensure that after they pass some sort of bureaucratic procedure they will continue doing business as usual in Colombia, in terms of trafficking and enjoying their wealth and the illicit assets they control,'' said José Miguel Vivanco, who directs operations in Latin America for Human Rights Watch.

In the talks with the government that began last fall, Mr. Castaño roiled his fellow commanders by recommending that they accept modest prison terms for their crimes and to surrender their ill-gotten fortunes, vast tracts of land and foreign bank accounts. "He openly expressed that these groups should demobilize, even if it meant paying a few years of jail time or confinement," said someone who sits at the table.

He had already inflamed them by publicly acknowledging the paramilitary group's role in assassinations and massacres, admitting that 70 percent of its funding came from the cocaine trade and calling on the commanders to stop trafficking. Eighteen of those men, including Diego Fernando Murillo, Salvatore Mancuso, Iván Roberto Duque and Mr. Castaño's older brother, Vicente Castaño, were recently classified as major drug traffickers by the United States Treasury Department.

Diplomats said the paramilitary leaders were prepared to serve time under house arrest, in their own homes, as long as they could keep their assets. But the commanders balked at imprisonment and forfeiture, and were adamant about gaining a guarantee of protection from American extradition requests, which could result in trial in the United States and long prison terms.

Rivalries, exacerbated by the threat of extradition, touched off an internecine war in the 15,000-member paramilitary group. That battle ended, officials and diplomats said, with Mr. Castaño's disappearance and the emergence of commanders who American officials say are major drug traffickers.

Despite Mr. Castaño's disappearance, some who sit at the peace table, like the Roman Catholic bishop Julio César Vidal, said in interviews that they doubted that the paramilitaries would battle with the state, since the paramilitaries are likely to get the best deal with Mr. Uribe.

Still, the possibility of blowback has been worrisome throughout the talks because the paramilitaries, unlike the rebels, are entrenched in Colombia's institutions, including the military, the police and the attorney general's office. Its fighters control whole neighborhoods in many Colombian cities, and the group has been supported in the past by wealthy and influential Colombians.

"They are politically very able, which the rebels are not, and they are more popular in certain areas," the Western diplomat said of the paramilitaries.

In a tour in early May of Córdoba, a state in the north that is the traditional heart of the paramilitary movement, it was clear that contrary to the government's assertions, the paramilitaries enjoyed a lock-down control that made them more influential than the traditional enemies of the state, the left-wing guerrillas, ever were. Interviewed here in this town in Córdoba where talks are taking place, a local commander said the organization did everything from paving roads to paying teachers' salaries to punishing law-breakers, even summarily executing those who violate paramilitary edicts.

"We are the de-facto state in all areas we occupy - in health, in education, in roadwork, everything that the state should offer," said the commander, who goes by the nom de guerre Miguel Antonio. "We are the law here."

The Self-Defense Forces also draw strength and financing from their close alliance with Colombia's most infamous drug cartel, the Norte del Valle group, which American officials said recently had exported more than 500 metric tons of cocaine worth $10 billion to the United States since 1990. In an indictment against nine cartel members unsealed in Washington, American officials accused the Self-Defense Forces of protecting the cartel's drug routes, laboratories and members.

The Drug Enforcement Administration, which has extensive operations in Colombia, said the group was even more involved in drug trafficking than were the left-wing rebels of the Revolutionary Armed Forces of Colombia, which in recent years have lost control of many of the country's drug-producing regions to the paramilitaries.

"They pale in comparison," a D.E.A. official who analyzes Colombia's drug trade said of the rebels in a recent interview.

On the surface, this verdant region is one of tranquillity and prosperity. Cattle graze as far as the eye can see, and people here say the economy is chugging along. Many here claim to live in one of the safest parts of Colombia.

Miguel Antonio, the local commander in Santafé de Ralito, denies that the group is involved in drug trafficking, or that it would ever battle the government. But he also made clear that paramilitary commanders were not about to serve jail terms, not after they embarked on a war against the rebels because of the government's inability to control its own territory. "We're illegal," he said, "but we're legitimate."

Sitting in his rambling house, drinking coffee and taking calls from friends congratulating him on his 51st birthday, Miguel Antonio pointed to his pet jaguar, Freckles. "Would you like me to put you in a cage?" he asked rhetorically. "Neither would my pet jaguar."

He also stressed that the federation was negotiating from a position of strength. "We are not defeated," he said. "We are strong."