Another summer, another bloody campaign. There is an inevitable and depressing sense of deja vu about the latest wave of ETA bombings and shootings. In the space of five days, ETA has detonated a carbomb in the commercial and historical centre of Madrid, blasted a Guardia Civil barracks in the Castillian province of Soria, and shot a local councillor in the Andalusian capital of Malaga. This is the most intense series of attacks carried out by ETA since the group ended its 15-month ceasefire last December.
The capacity to strike almost simultaneously at different points far from the Basque Country is a clear demonstration that ETA is far from the spent force it was thought to have become before the ceasefire. Moreover, this escalation takes place at a time when relationships between the moderate Basque nationalist parties and central government in Madrid are more dangerously tense than at any time since Spain's transition to democracy in the late 1970s. The strategy behind ETA's campaign is to stretch this tension to breaking point, bringing about a full-scale confrontation between defenders and opponents of the politically explosive concept of "Basque sovereignty".
This is all a far cry from the situation in July, 1997, when it seemed for a few days that ETA was on its last legs. The cold-blooded killing of Miguel Angel Blanco, a young local councillor for the ruling, centreright Partido Popular (PP) sparked unprecedented protests by millions of Spaniards. Many observers saw these demonstrations as a watershed in the struggle against terrorism, especially when many thousands of Basques joined the demonstrations in the nationalist heartlands.
Against expectations, however, ETA and its radical nationalist supporters in Herri Batasuna emerged a year later with enhanced political capital. This was perhaps a measure of how much moderate Basque nationalists perceived, however mistakenly, the huge demonstrations as not only anti-ETA but anti-Basque. In any case, by September, 1998, the moderates were ready to take a huge risk, modelled on Hume-Adams and the ensuing Irish peace process. They declared that the 1979 Statute of Autonomy, which concedes very extensive self-government to three Basque provinces, was "exhausted". They signed the Lizarra Pact with ETA's supporters which effectively called for self-determination for both the Spanish and French Basque regions. ETA's ceasefire followed a week later.
Mr Jose Maria Aznar's PP government now faced a dilemma. The chance to heal a cancerous wound from the Franco period was enormously attractive. However, the "indissoluble unity" of Spain is a cornerstone of the 1978 Spanish constitution, guaranteed by the armed forces. The Lizarra Pact threatened to open a Pandora's box, kept firmly shut for 20 years. In the end, Madrid stone-walled, and ETA returned to terrorism last December. This leaves the moderate Basque nationalists, whose minority government in the Basque regional parliament has been propped up by ETA supporters, out on a limb. They definitively broke ranks with the Spanish democratic parties in joining the Lizarra Pact. But they cannot indefinitely accept the support of a group linked to active terrorism.
Mr Aznar's party demands early elections, which could result, for the first time ever, in a non-nationalist coalition running the Basque autonomous region. ETA is betting that such a situation would drive many moderates into its camp and set the scene for full-scale conflict. It has shown, in the past week, just how effectively - and cruelly - it can advance its own scenario. Knee-jerk responses are likely to be counter-productive.