Argentina's military rulers left office two decades ago, but the seven years they were in office have cast a long shadow over the country.
Official figures say 9,000 people were kidnapped, tortured and killed in what became known as the Dirty War.
But most believe the real number to be closer to 30,000.
Many of those responsible were initially prosecuted, then granted amnesties by the weak and frightened civilian governments that followed the military. They've since lived as free men.
But the battle to bring them to justice has never waned.
Protesters have long been demanding Astiz's arrest
Every Thursday afternoon for the past 20 years a group of women has marched quietly in front of the presidential palace in the centre of Buenos Aires.
They are the mothers and grandmothers of some of those kidnapped and killed by the military government that ruled Argentina for seven years and they have been demanding to know what happened to their loved ones.
Now President Nestor Kirchner has surprised many and taken a huge step in meeting their demands.
The military came to power in March 1976 after a period of political instability and growing violence.
They began a systematic campaign to wipe out left-wing terrorism - but the terror carried out by the state exceeded anything previously seen in Argentina.
Students, union leaders and political activists were dragged from their beds in the middle of the night and never seen again.
They were tortured at secret locations and some were even thrown, bound and gagged, from planes and helicopters into the River Plate and Atlantic Ocean.
Many Argentines reserve a special hatred for the man known as the blond angel of death, the former naval captain, Alfredo Astiz.
Kirchner has dared to act where predecessors vacillated
His arrest and extradition to Spain will do much to convince a sceptical people that President Kirchner means business.
Captain Astiz ran a military death squad and boasted of being the best trained man in Argentina to kill politicians or journalists.
The civilian governments that followed the departure of the military in 1983 initially prosecuted the armed forces officers but then brought in a series of amnesties and pardons.
It has increasingly looked like the Dirty War suspects would grow old with impunity.
But now President Kirchner has done what none of his predecessors dared to do - and those Argentines who refused to give up the fight may now get the justice they have been yearning for.