CAN a terrorist organisation ever be wholly defeated? The British government’s willingness to bargain with the Irish Republican Army suggests that only long negotiations can bring violence to an end, and even then it can flare up again. Yet in Madrid, they think otherwise. The deadly First of October Anti-Fascist Resistance Group (Grapo) that emerged from murky 1970s Maoism has ceased to be a threat, and its members are in jail. Could that happen to the separatists of Basque Homeland and Liberty (ETA), Europe’s last big domestic terror group?A much-weakened ETA has done a lot to wean itself off violence. It has not killed in Spain for four years. In October 2011 it unilaterally declared a permanent ceasefire. Those who called it remain in control. But ETA still has arms and explosives, probably buried in waterproof containers in French forests. A heated debate continues between ETA’s leadership, its 700-odd jailed members and its political allies over whether to give up the weapons.Many Basques want the Popular Party (PP) government led by Mariano Rajoy to offer ETA a carrot, but it refuses. A highly…