Ivan Briscoe, Editor English edition of El Pais

The scenes of deformed, twisted metal are all too familiar in Madrid. So horrifying and upsetting were the images of the March 11 attacks last year that newspapers and television stations agreed with victims' groups to stop showing them. But 15 months later, the images come back, like a phantom visitation, yet this time in a different, bigger city, a place that madrilenos look to and adore. Words are inadequate to describe how this feels; a numbing despair, perhaps

Madrid, however, has generated its lessons. The first is obvious, but very hard to digest: this is not over yet. If they were not suicide bombers, then they may be ready to continue the campaign, just as the March 11 ring sought to do with an attack on a high-speed train. Second, avoid at all costs politicizing the bombings, for the dispute will wrangle on and amplify and end up turning corpses into cheap arguments - which is what the terrorist themselves maintain.

In Spain, the timing of the attacks three days before the elections served to polarize political opinion on a multitude of issues (there is no agreement any more in Madrid). This will not be London or Britain's problem.

But in other ways, venom, as Ken Livingstone warned, will seek its way into the body social and politic. This is the other phantom waiting to reappear.