It used bullets and bombs for nearly 40 years, killing more than 800 people as it fought for an independent Basque homeland. But in the end, the separatist group ETA owes its demise to an act of terrorism it did not commit.

The Islamic terror bombings of March 11, 2004 in Madrid caused such widespread revulsion in Spain, even among Basque nationalists who support ETA’s goals if not its methods, that they are widely seen as marking the beginning of the end of ETA.

The Madrid carnage — ten backpack bombs on crowded commuter trains that killed 191 people and injured more than 1,500 others — suddenly made it politically unthinkable for ETA to keep up its own brand of killing.

ETA’s last fatal attack goes back a bit further, to a car bombing that killed two policemen in the northern Navarra region in May, 2003. Since the Madrid attacks, ETA has still detonated bombs — some big, most small — but taken pains to avoid fatalities, attacking empty buildings and phoning in warnings. In some cases it has even placed warning signs on its bombs.

“Paradoxically, and through dumb luck, the March 11 attacks essentially marked the end of ETA terrorism,” said Javier Ortiz, a political analyst who works for Basque radio and television and writes for the newspaper El Mundo.

More than 200 ETA members have been arrested in recent years, including several top leaders, and the Socialist government of Prime Minister Jose Luis Rodriguez cited this alleged weakness in the group as a reason to offer it peace talks last May if it renounced violence, saying the time was right to seek peace.

Jose Luis Zubizarreta, a former member of the Basque regional government, said yesterday after ETA declared what it called a permanent ceasefire that the group “has reached the end of a cycle. It has exhausted itself.”

But Ortiz dismissed this argument, saying ETA still has plenty of money, access to the international market for weapons, hundreds of people willing to join up and around 50 active commando members.

“This defeat has been political, and mainly social,” Ortiz said in a telephone interview. “Basques in general and even ETA’s supporters have reached the conclusion — correctly, I think — that ETA can achieve more through peaceful, political means than by setting off bombs,” Ortiz said.

Ortiz said Zapatero will probably now engage in “discrete” negotiations with ETA and has the historic chance to be the Spanish leader that presides over the end of Euskadi Ta Askatasuna — a nationalist liberation movement for its supporters, but a gang of terrorists for most Spaniards, the European Union and the United States.

What was surprising in the statement ETA issued yesterday was its use of the word permanent. This was unprecedented for a group which has declared ceasefires before, the most recent one in 1998, lasting 14 months, only to revert to violence.

Zapatero won parliamentary support last May for his offer to negotiate with ETA if it renounced violence. But he insisted those talks would not involve concessions to ETA and centre on terms for the group’s formal dissolution.

ETA responded with dozens of relatively low-level bombings, many targeting businesses in the Basque region, and more than half a dozen in the past month alone. — Associated Press