TERROR'S REIGN IN SPAIN

Unlike the United States, Spain is used to terrorism. When the earth shook and windows shattered near Madrid's busy Atocha train station on March 11, nearby residents thought they knew what it meant: another attack by Basque separatists fighting a 40-year battle for independence. The routine was all too familiar. There would be sirens and swearing, followed by silence at noon, the traditional show of respect for the dead, and solidarity against the terrorists. Then life would go on.

But what went on-and on and on-were the blasts themselves. Ten in all, nearly simultaneous, up and down the busy commuter rail line crammed with workers headed for the office, children headed for school, tourists headed for a day of sightseeing. This, it quickly became apparent, was unlike anything Spain had experienced before.

For a country of 40 million, the 201 deaths on March 11 approached, on a

per-capita basis, the death toll suffered by the United States on Sept. 11. In 40 years of fighting, Basque terrorism had claimed some 800 lives; in a single day that number leapt 25 percent. Never before had the separatists taken more than 118 lives in an entire year, and their single-deadliest bombing to date had killed just 21. Such numbers paled in comparison to March 11, which would go down in the record books not only as the deadliest terrorist attack in Spain, but in all of Western Europe.

Almost at once, many Spaniards began to suspect that the Basques weren't behind the bombings at all. There were too many differences from previous attacks: no advance warning, no immediate claim of responsibility, no careful focus on government and law-enforcement targets. Only the traditional moment of silence at noon could temporarily muffle the emerging debate: Was this the work of homegrown terrorists or al-Qaeda?

With elections just three days away, the answer to that question was even more pressing than it might otherwise have been. If the Basques were responsible for the bombings, the Popular Party of Prime Minister Jose Maria Aznar would likely enjoy an easy victory over the opposition Socialists, a party widely viewed as soft on the separatists. But al-Qaeda was another matter. With the Iraq War already opposed by up to 90 percent of Spaniards, any reprisal against America's leading ally in mainland Europe was sure to weaken the government's standing, and possibly hand the election to the Socialists.

Jose Zapatero, the Socialist leader, wasted no time in accusing the government of downplaying evidence against al-Qaeda-a charge vehemently denied by Mr. Aznar and his handpicked successor in the election, Mariano Rajoy. Still, by Friday night, when an estimated 8 million people marched in protest parades all across the country, sorrow had clearly turned to anger. Two days later, Spanish voters turned out Mr. Aznar's ruling party, dealing a stunning blow to the Bush administration's international coalition in Iraq, and, perhaps, to the entire war on terror.

Despite pleas from the White House, Mr. Zapatero pledged to pull Spain's 1,300 troops out of Iraq. "Unless there is a change, in that the United Nations takes control and the [U.S.] occupiers give up political control, the Spanish troops will come back, and the limit to their presence is June 30," he vowed. Their numbers are small-Spanish soldiers represent just 1 percent of the international peacekeeping force-but the withdrawal could undermine Mr. Bush's constant claim that the Iraqi reconstruction is an effort by the international community, and not just the United States.

There could be repercussions far beyond the Iraqi borders, as well. Experts worry that al-Qaeda and its sympathizers will view Mr. Zapatero's political upset as a victory for violence, and that they'll try to re-create their success by targeting the elections of other coalition partners, including, perhaps, the United States.

"The terrorists have killed 200 people and defeated the government-they have achieved all their objectives," declared Gustavo de Arustegui, the foreign-policy spokesman for the Aznar government and a member of Parliament. "I think the terrorist attacks were politically planned. We have transformed terrorists into political actors with this."

A letter published in an Arabic newspaper on March 17 backed up that view. "Praise be to God who gave us this victory in the conquest of Madrid ... where one of the pillars of the axis of Crusader evil was destroyed," said the letter signed by the Abu Hafs al-Masri Brigades, an al-Qaeda ally that claimed responsibility for the Madrid bombings. The group said it was calling a truce with Spain until the new government could deliver on its promise to pull out of Iraq.

Still, investigators can't be sure that the al-Masri Brigades even had a part in the Madrid bombings. They have previously taken credit for events clearly beyond their control, such as the blackout that crippled the U.S. Northeast last summer. Besides, Spain has plenty of enemies closer to home: In addition to Basque terrorists, who may have played some sort of supporting role, Moroccan terrorists are known to travel with relative ease across the narrow strait separating the two countries.

Indeed, a week after the bombings, Spanish investigators appeared to be focused on the Moroccan connection. Three Moroccans and two Indians faced a closed-door court hearing on March 18, and police were reportedly searching for some 20 other Moroccans who may be linked to last year's attacks in Casablanca that killed 45.

One of the Moroccans, Jamal Zougam, ran a mobile-phone shop in Madrid, and police now believe such phones were used as detonators in the blasts. Mr. Zougam's reported ties to the Moroccan Islamic Combatants Group, a little-known arm of al-Qaeda based in North Africa, could indicate a dual motivation for the attacks: Spain has had tense relations with Muslim Africa for centuries, ever since the Spanish rulers expelled the Moors in a bloody 15th-century crusade. More recently, Spain fought a brutal colonial campaign in the mountains of northern Morocco in the 1920s, and Madrid still rules over two tiny colonies carved out of the Moroccan coast. In 2002, the two countries actually fired shots in a skirmish over the tiny Mediterranean island of Perejil.

Whatever the ultimate motivation for the attacks, terrorism experts worry they may indicate a new effort by al-Qaeda to exploit old hostilities and gain new allies. European nations, wary of flare-ups at home, may be even more hesitant to cooperate with Washington in the war on terror. More terrorist groups and fewer allies would make the effort to protect America infinitely more difficult and more expensive, and the Bush administration could find itself isolated on the world stage.

That's a scenario that can't please Mr. Bush's campaign advisers. With a shaky economy and a looming election, the president can ill afford to lose his advantage in foreign affairs. More terrorist attacks, even far from home, could bolster the Democrats' contention that Mr. Bush's policies have made the world a more dangerous place.

Spanish voters bought that argument. Will American voters do the same?