By JUAN FORERO
 
BOGOTÁ, Colombia, July 28 - Trading combat fatigues for business suits, three top commanders of Colombia's right-wing death squads emerged from their government-granted haven in the north to speak before the country's Congress on Wednesday, professing firm commitment to fragile peace talks aimed at disarming their 15,000-member paramilitary force.

Traveling with government-issued 48-hour safe-conduct passes shielding them from arrest and, in the case of one of the three, extradition to the United States on drug charges, they flew to Bogotá on a military plane and were escorted to the ornate Capitol building by state security forces.

Before a packed gallery of congressmen, diplomats and reporters, Salvatore Mancuso, indicted in the United States on charges of trafficking 17 tons of cocaine, said, "I come here in an irreversible mission of peace."

"I believe in God, the god of hope, of love, of forgiveness," said Mr. Mancuso, in an hourlong speech to a chamber that usually limits speakers to 20 minutes. "I'm a man of business, head of a family, thrown into the terrible mouth of war."

Mr. Mancuso and two fellow commanders of the United Self-Defense Forces of Colombia, Ramón Isaza and Iván Roberto Duque, were invited to speak by members of Congress who have said the paramilitary group is misunderstood. It was an invitation the three, eager to alter their reputations as mass killers and criminals, eagerly accepted.

Their appearance infuriated those who want justice for the thousands of Colombians killed by paramilitaries in their long war to erode support for Marxist rebels. The United States has classified the group as a terrorist organization, and has indicted Mr. Mancuso and four other commanders for trafficking mutton loads of cocaine to the United States.

In an old-fashioned speech using the flowery language of Colombia's caudillo politicians, Mr. Mancuso, the college-educated son of an Italian immigrant, cast his group as an ally of the state in the fight against rebels, who once controlled much of this vast country. Using images close to every Colombian's heart, from the independence hero Simón Bolívar to God to the Nobel laureate Gabriel García Márquez, he stressed his group's allegiance to democracy and Colombia's future.

"History will recognize the goodness and greatness of our cause," he said. "We are defenders of a free Colombia and its institutions."

And he said that as "compensation for our sacrifice for the fatherland," he and other commanders "cannot receive jail."

As Mr. Mancuso finished, a protester in the journalists' gallery held aloft a picture of Senator Manuel Cepeda, who, like at least 1,500 other leftist politicians, was slain by paramilitary gunmen. "No more impunity," shouted the protester, Lilia Solano, a law professor, shaking and with tears flowing down her face. "No more laws of forgiveness and forgetting."

International rights groups, foreign diplomats and some Colombian lawmakers said allowing the paramilitary commanders to address Congress would only help the group whitewash its image and improve its position in peace talks. They fear the commanders will secure a deal permitting them to avoid jail time and having to turn over land and other ill-gotten gains.

"This is a very dangerous game and awful precedent," said José Miguel Vivanco, the Americas director for the New York-based group Human Rights Watch. "What this kind of circus does is raise the expectations for these individuals to strengthen their position by manipulating the public, with some sort of family-values speech."

Congressman Gustavo Petro, a vigorous critics of the paramilitaries, said: "What we see is the state and justice submitting themselves to narco-traffickers. This shows the great power paramilitaries and narco-traffickers have over Congress."

Wilson Borja, another congressman, who was badly wounded by paramilitary gunmen in December 2000, said that a measure approving the men's appearance had been slipped through the Congress without most members actually realizing what they were voting on. "This is bad because it is illegal,'' he said. "In no instance did the Congress approve this."

Outside, in the giant Plaza Bolívar, anchored by the stoic statue of the Liberator that has served as a meeting place for protesters and lovers for decades, hundreds of people bused in from the countryside shouted, "Viva La Paz," or long live peace, in an orchestrated show of support. Participants said they were given T-shirts that read, "We are builders of peace," and long banners proclaiming allegiance to the peace process.

"They got us together, they organized us," said Luis Parrado, 50, a street vendor, pointing to several men in bright windbreakers who bused Mr. Parrado and others from the southern city of Villavicencio.

But there were also relatives of people killed by the paramilitaries, carrying coffins and photographs of their loved ones. Some yelled, "Mancuso, fascist, you narco-terrorist."

Heavily armed police officers, dressed in black antiriot gear, quickly removed the protesters, who went peacefully.

Hundreds who supported the paramilitary presence were permitted to remain, hailing President Álvaro Uribe and Mr. Mancuso.

"We want to support the president's peace talks," Rafael Quintero, 45, an indigenous leader who lives in the heart of paramilitary territory in northern Colombia. "It's a good process."

Mr. Uribe's government has faced a chorus of criticism over continuing negotiations because the paramilitaries, who claim to have enacted a cease-fire, have continued to carry out assassinations, kidnappings and other crimes. The talks are shaky in part because the government wants the paramilitary commanders to serve at least five-year jail terms; the commanders says they will withdraw from talks unless the government drops that condition. But on Wednesday, it was Mr. Mancuso who got the last word. "Here, with me, are the wounded heroes of the war, the ones who survive and the ones who died," he said. "Here are those who have toiled without rest defending this Colombia."

Mónica Trujillo contributed reporting for this article.