BUENOS AIRES, Argentina ---- They are old and balding now, the 15 defendants standing trial before a three-judge panel near the Argentine capital's bustling port. But prosecutors say they were once the feared henchmen of a brutal military dictatorship. Argentina has tried military men before. But this trial, of officers and policemen who ran clandestine torture centers known as the Athletic Club, the Bank and Olimpo, is one of a string of new proceedings that by next year will close some of the most emblematic cases of alleged state terrorism under Argentina's 1976-1983 dictatorship. With former generals and admirals well into their 70s and the courts emboldened to hand down severe penalties, Argentina is finally close to delivering justice for the estimated 30,000 people killed by state security services during the 'Dirty War,' including some who were thrown from airplanes after being tortured and sedated. 'I think and I hope this is the beginning of the end of a long process that began in 1983 with the return of democracy,' said Gaston Chillier, director of the Center for Legal and Social Studies, a Buenos Aires rights group. 'Next year will be especially critical.' The trials in Argentina come as other South American countries grapple with delivering justice for the victims of dictatorships and government-linked death squads. In Brazil, President Luiz Inacio Lula da Silva is proposing a commission to investigate allegations of torture by the military during that country's 1964-1985 dictatorship. In Peru, a former president, Alberto Fujimori, was convicted of murder in April for death-squad activities during his 10-year rule. And in Colombia, army generals and colonels accused of widespread human rights abuses are for the first time being investigated by civilian prosecutors. Among the countries that have most aggressively sought to address past crimes is Chile, which has convicted 277 members of Gen. Augusto Pinochet's 16-year dictatorship of myriad rights abuses, according to New York-based Human Rights Watch. But no country has gone after former state agents as sweepingly as Argentina. Using ordinary penal law and the criminal courts, prosecutors have won convictions against about 60 rights abusers since 2005. An additional 627 former military officers, policemen and officials have been charged. In all, 325 cases are open nationwide, most involving former members of the security services accused of kidnapping and killing leftists, according to the Center for Legal and Social Studies. Achieving justice has not been easy. Barracks revolts in the 1980s led to a 'full-stop' law that ended investigations and a 'due obedience' law that absolved those who said they were following the orders of superiors, a defense rejected at the Nuremberg trials. In the 1990s, President Carlos Menem pardoned those who had been convicted. But in 2005, Argentina's Supreme Court annulled the amnesties, and a revitalized judicial system began to prosecute. Convictions have been won against once-influential figures in Argentina's security forces, including Luciano Menendez, a former regional army commander, and Miguel Etchecolatz, a former Buenos Aires provincial police commissioner. Now, though, the men on the block include some of the dictatorship's most notorious figures. Among them are former Gen. Jorge Rafael Videla, who led the junta that governed after a 1976 coup, and Argentina's last dictator, Reynaldo Bignone. There is also Alfredo Astiz, nicknamed 'Blond Angel of Death.' Using his boyish good looks, prosecutors say, Astiz infiltrated a leading human rights group in 1977. That led to the abduction and murder of three of the group's founders, a journalist and two French nuns. The courts here have requested declassified U.S. cables that detail what the United States knew about Argentine military operations in the war against leftist guerrilla groups. Carlos Osorio, who oversees the Argentina project for the National Security Archive, a Washington policy group that compiles government documents, said Argentine prosecutors may end up using several hundred of about 8,000 declassified State Department documents. Those papers show how U.S. Embassy officials compiled reports on such issues as the pursuit of suspected guerrillas outside Argentina's borders and details on the abductions by Argentine intelligence operatives. 'The documents that have been declassified are very rich, but there are some holes, and they can be filled with the documents in the hands of the American intelligence agencies,' Osorio said. Delia Barrera, who was tortured in the Athletic Club detention center in 1977, is now among the witnesses for the prosecution. Speaking outside the courtroom on a recent day, she recalled how her husband told her to fight on for him after he was led away by military officers. She never saw him again. 'For me, this is a fight for justice, for memory, for truth -- it's a commitment for life,' she said. 'Everything I do and will continue to do, until the last day of my life, is a commitment with those words, which have stayed with me in my soul.' 