The bombs that exploded early Thursday morning in Madrid, killing at least 182 people in the single deadliest terrorist attack in modern European history, turned the city's Atocha train station into a scene of carnage and transformed Spain's political landscape three days before general elections.
Though no one has claimed responsibility for the 10 blasts that tore into trains and commuter railway stations during the morning rush hour, the police and government leaders blamed ETA, the separatist group demanding independence for the Basque region of northeastern Spain.
The deadly explosions thus blew every issue off the agenda other than the government's war on ETA, which the ruling Popular Party (PP) had made a key plank of its electoral platform.
World leaders who have joined the US-led war on terror were quick to draw analogies with terrorist incidents elsewhere. "Terrorism has once again shown it is prepared to stop at nothing in creating human victims," Russian President Vladimir Putin said. "An end must be put to this. As never before, it is vital to unite forces of the entire world community against terror."
"This terrible attack underlines the threat that we all continue to face from terrorism in many countries and why we must all work together internationally to safeguard our peoples against such attacks and defeat terrorism," British Prime Minister Tony Blair said.
Domestically, the attack appeared to seal the ruling party's victory at the polls Sunday. "Logically this will benefit the Popular Party," says Jose Alvarez Junco, a political analyst at Madrid's Complutense University. "They are the ones who are seen as being toughest on ETA, who have taken a hard line with them."
Mariano Rajoy, the Popular Party candidate for prime minister, called off the rest of his party's election campaign following the explosions, as a mark of respect, and other parties followed suit. But analysts said the 5 percent lead the Popular Party enjoyed over the opposition Socialists in the latest opinion polls would probably grow by Sunday, holding out the prospect of an absolute governing majority with no need for coalition partners.
Socialist leader Jose Luis Rodriguez Zapatero had hoped to turn Spanish voters' overwhelming opposition to their government's support for the war in Iraq to his advantage. But the only war Spaniards will likely have on their minds when they go to the polls will be their own longrunning battle against Basque terrorism.
Suspicion immediately fell on ETA (Basque Homeland and Liberty), which until Thursday had killed nearly 850 people in its 35-year war for Basque independence, partly because 10 days ago police intercepted a Madrid-bound van packed with more than 1,000 pounds of explosives, and blamed ETA. On Christmas Eve, police said they had thwarted a bombing at a Madrid railway station and arrested two suspected ETA members.
"It is absolutely clear that the terrorist organization ETA was seeking an attack with wide repercussions," Spanish Interior Minister Angel Acebes said Thursday.
The leader of a banned political party linked to ETA, however, said he did not believe the group was responsible for the bombings, which were on a far larger scale than any attack the group had launched previously, and which occurred without the warnings ETA usually calls in before its attacks. Arnaldo Otegi, spokesman for Herri Batasuna, suggested in an interview with Radio Popular that "Arab resistance" elements were behind them.
It was not clear why ETA, which has traditionally targeted government institutions, policemen and political opponents with shootings and carbombs, might have scaled up its operations so dramatically as to explode 10 bombs within a period of two hours and kill scores of random victims.
"I would guess it is because they are much weaker than before and this is a desperate measure," says Jaume Soriano, a professor at the Autonomous University of Barcelona. "It looks like they have lost control over their own forces."
One international terrorism expert suggested that if ETA is responsible for the attack, it may have found inspiration for its novel tactics elsewhere. "Even if ETA has been partially wiped out there is still a radical core that has survived and this core apparently has no qualms about killing mass numbers of people," Joachim Krause, a security expert at Kiel University in Germany, told Reuters. "They have perhaps taken Al Qaeda as a role model ... they've seen that's how to get media attention."
Not that ETA has ever lacked for media attention in Spain, especially during the current election campaign, which has focused heavily on the government's fight against the Basque separatists.
Prime Minister Jose Maria Aznar, who survived a 1995 ETA assassination attempt, has cracked down hard on the armed separatist group, outlawing Herri Batasuna and closing Basque newspapers with suspected ties to ETA. The police arrested 179 suspected ETA members last year, bringing the total to 650 since 2000.
The campaign appeared to be working: Last year, ETA claimed only three killings, down from 23 in 2000.
While Mr. Rajoy, a former interior minister, boasted of these successes, the Socialist leader Mr. Zapatero suffered from an alliance that his Catalan branch party forged in the regional Catalonian government with the Republican Catalan Left (ERC) party, whose leader held secret talks in France last January with ETA leaders.
Two weeks later, ETA declared a truce in Catalonia, spurring charges that the ERC had negotiated with an organization that both the European Union and the United States have characterized as a terrorist group. The Socialist Party, through its Catalan branch, was weakened by those charges.
But Zapatero's main difficulty has been in countering a widespread sense among voters that eight years of Popular Party rule has been good for them economically.
"Things are going well now, the economy is good," says Victoria Cano, a cook in Madrid. "And the opposition isn't convincing."
Aside from terrorism and crime, unemployment tops the nation's list of concerns, and the Popular Party record in job creation has impressed voters. After eight years of uninterrupted economic growth, averaging 3 percent a year, the government has brought joblessness down to 11 percent, from 21 percent in 1996.
Buoyed by the country's recent prosperity, many Spaniards are fearful of slowing the momentum that Mr. Aznar and his hand-picked successor, Rajoy, are touting. "The last eight years have gone well, economically speaking," says Ignacio Forcada Barona, a professor at the University of Castilla-La Mancha, "and people are going to vote with their pocketbooks. They want to protect what they have."
In the wake of Thursday's atrocity, Spaniards will also be voting with their emotions, and that, too, is widely expected to benefit Rajoy, who has long presented the Popular Party as the only party willing and equipped to do what it takes to eradicate the ETA. "The PP has based its entire campaign on the antiterrorist fight, and the attack will feed that image," says Professor Soriano. "Before, I did not think the PP would win an absolute majority, but today I think they will."