By Steve Kingstone
BBC News, Madrid
Spanish leaders attended the funeral of the two Civil Guards in Majorca
The charred wreckage of a patrol car in Majorca, and the shattered facade of a police barracks on the mainland represent a grim birthday message from Eta, as the Basque militant group marks the 50th anniversary of its founding.
Wednesday's car bombing in Burgos, which caused extensive damage but only minor injuries, was characterised as a "failed attack" by Spain's Interior Minister, Alfredo Perez Rubalcaba. But those words rang uncomfortably hollow just 24 hours later, when a second bomb in the Majorcan resort of Palmanova claimed the lives of two Civil Guard officers.
Half a century after a small cell of Basque student radicals adopted the name Euskadi ta Askatasuna (Basque Homeland and Freedom), Eta has sent a clear message that reports of its demise have been greatly exaggerated.
During the group's fledgling years, its young founders ran a covert campaign to preserve the Basque language, which had been outlawed by General Franco. But the goal soon became altogether more ambitious: an independent state, to take in historic Basque lands spanning parts of south-western France as well as Spain.
Eta resorted to arms in 1968, killing a civil guard police officer at a checkpoint in the Basque province of Guipuzcoa. It has since claimed 827 further lives, according to the Interior Ministry. Today, 501 men and 84 women are in Spanish jails - accused or convicted of terrorism-related crimes.
Top suspects arrested
Without doubt, the organisation is weaker than it was. At the height of its violence in 1980, Eta claimed 92 lives, compared with four fatalities in 2008, and three so far this year.
The Majorca attack was the deadliest attributed to Eta since December 2007
The Spanish authorities have sought to take credit for that weakness, stressing the decisive impact of high-profile arrests, often in partnership with French police. Since May 2008, officers have detained four suspects described as Eta's political or military "commanders".
"Eta has been acknowledging internally that they are in a very critical situation," explains Rogelio Alonso, a terrorism expert at the King Juan Carlos University in Madrid. But he adds a caveat: "although they are weakened, it only takes a few people to plant a bomb. So they remain highly dangerous."
Politically, Eta is isolated. For while 24% of Basques support its goal of independence, according to the latest Euskobarometro poll of public opinion, only 1% offer "total support" for its methods.
The prospect of renewed dialogue with the government in Madrid is remote, following the failure of earlier talks during an Eta ceasefire, starting in March 2006. The peace was broken by a bomb at Madrid's Barajas airport in December that year, and Eta officially ended its ceasefire six months later, after contact with the politicians petered out.
Today, Eta has no legally-recognised political representatives. Its favoured candidates were barred from standing in recent regional elections by judges in Madrid; meaning that, for the first time, radical separatism is unrepresented in the Basque parliament. Without little or no influence in the political arena, the group is again making its point with the gun.
The car bombing in Burgos caused extensive damage but no deaths
Some former militants have turned their back on violence. They include Julen Madariaga, a founder member of Eta, who is now in his late seventies.
"Eta has not had the lucidity or courage to realise that times have changed," he told the El Pais newspaper recently. "I realised that violence achieves nothing, but others lacked the balls to admit it."
Madariaga encourages others to follow him into Aralar, a youthful political party which advocates Basque separatism but rejects violence. It surprised many by winning four seats in the regional election, doubling its vote of 2005. But the biggest winner was the Socialist Party, which now leads a coalition government in the region - having ended three decades of rule by Basque nationalists.
Eta has described the Socialist administration as a "priority target". There is no reliable figure for the number of militants who might be able to deliver on that threat, but many of the group's current followers are young, and often related to the older generation of serving prisoners.
Recently, one unnamed militant mocked the government's claim that the group was terminally weakened. "All Spanish interior ministers dream of doing away with Eta," he said, as quoted by the separatist newspaper Gara. "But to do that, the education minister would first have to redraw the map of the Basque Country and rewrite the textbooks."
In the wake of the Mallorca killings, a stern-faced Prime Minister Jose Luis Rodriguez Zapatero again spoke of defeating Eta "definitively".
But after the bloodiest week in months, Spaniards may wonder whether he was speaking more out of hope than expectation.
Correction 4 August 2009: In a previous version of this story we mistakenly said that Eta's first victim was a police commander in San Sebastian, when in fact he was a civil guard officer killed in Guipuzcoa.