Attack by Basque Separatists Fails As Support Dims for Terrorists

SPAIN'S opposition leader could easily become the next prime minister, thanks to a powerful car bomb meant to kill him but that left him unscathed and ever more popular.

The failed attack last week was another blow to Western Europe's most active domestic terrorist group, ETA, which yesterday claimed responsibility for the attack.

This separatist group, whose name stands for ''Basque Homeland and Liberty,'' in the Basque language, has long sought independence from Madrid for some 2.3 million Basques.

The Basques, almost certainly Europe's oldest surviving ethnic group, live in three northern Spanish provinces and in part of southern France.

Since the attack last Wednesday, analysts also predict that the opposition leader Jose Maria Aznar's conservative Popular Party will make an even deeper sweep in municipal elections next month.

But ETA's terrorist campaign is now losing both supporters and members, which may now number fewer than 200, according to a government security source. Six hundred ETA activists are in jail. Yet few political leaders here expect the guerrillas, who have fought since 1968 for an independent Basque homeland, to call it quits and start talking peace, as in Northern Ireland.

Constantly on guard

Being on guard against terrorism has become ingrained in Spain, somewhat like being careful about big-city street crime in the United States. In Spain, cars cannot be parked beside key government buildings. Handbags and mail are scanned at even mundane offices.

''A car bomb could go off anytime. People are aware of it, especially in Madrid and the Basque region, where ETA tends to strike,'' says Paulino Baena, spokesman for the national Association of Victims of Terrorism, formed in 1981.

ETA's political wing, Herri Batasuna (Popular Unity), over the weekend reaffirmed its support of ETA's violence, which has killed nearly 800 people and wounded 3,000 in 26 years. Popular Unity just last month quieted dissident voices in its ranks who criticized the party line.

''This is a very long road,'' sighs Mr. Baena. ''We're progressing, but slowly.''

Yet the failed assassination of Mr. Aznar in Madrid seemed to stiffen the political resolve of the government, which insists it is the winning the slow, grinding fight against Europe's second-most deadly separatist group, after the Irish Republican Army.

Socialist Prime Minister Felipe Gonzalez called it an attack on democracy and joined the increasing number of people urging restrictions on Popular Unity, seen as a cheerleader for ETA.

''There are crimes which are clearly delineated in the law ... which until now have not resulted in judicial action,'' Mr. Gonzalez warned.

Popular Unity holds just two of the 350 seats in Spain's national parliament. But in the northern Basque region, the party has a bigger voice in the regional parliament and gets about 15 percent of the vote.

ETA's violence has turned away many voters from Popular Unity, and ever-larger peace marches occur after practically each new ETA attack. The Basque region's controlling party is the center-right Basque Nationalist Party, which seeks a Basque homeland without violence.

Instead of shutting down Popular Unity, Gonzalez, who has governed since 1982, has granted home-rule powers to Spain's 17 semiautonomous regions.

The Basque region has more power that any other region, including tax collection and running its own 5,000-member police force, which combats ETA along with the national police.

But Gonzalez's credibility has plummeted due to allegations that his security apparatus ran a state-sponsored dirty war against ETA last decade, killing 28 suspected terrorists. Several former senior security officials have been jailed while a judge investigates.

A hint at talks

Gonzalez and opposition leader Aznar agree that there can be no peace talks with ETA until it stops the violence, a stance that London also took with the IRA. The only official government-ETA talks were in 1989 in Algeria, but they ended quickly amid mutual accusations of bad faith.

But a spokesman for the moderate Basque Nationalist Party hinted it would explore talks with ETA even before the attacks end.

Those potential cracks in the political ranks may be enough to fuel what many analysts say are ETA's hopes that its violence will force the government into talks.

ETA appears more than willing to carry on the fight, even if it has to use younger, less-experienced operatives. Spanish media reported that ETA this month sent a fresh set of recruitment letters to disgruntled, often-unemployed youth in the northern Basque provinces. ETA also recently sent a different letter to businesses, pressuring them to pay a ''revolutionary tax'' or else.

These funds and ransom collected from the occasional spectacular kidnapping have boosted ETA's war chest.

But while ETA's numbers are dwindling, the Spanish -- especially those dozen people wounded in last week's car bomb -- are still well aware that the conflict is far from being resolved.