The tense political atmosphere in Spain in the period running up to the elections brought the PP to the edge of a political catastrophe. On one hand, José María Aznar was aggressively opposed to any dialogue with ETA, and based most of his campaign on the threat of terrorism (the September 11 attacks in New York reinforced his view of the war against the terrorists). On the other hand, Aznar's friendship with U.S. president George W. Bush led him to support the 2003 invasion of Iraq against the views of the overwhelming majority of the population (resulting in the biggest demonstrations ever seen in Spain since the restoration of democracy in the late 1970s). This left Aznar in a complicated situation: if Basque terrorists were proven to be responsible for the massacre, it would favour the PP's campaign, but if an Islamic group appeared to cause the blast, people might blame him for earning himself (and Spain) enemies.