On December 21, 1999, the Spanish Civil Guard successfully intercepted a van in Madrid that was loaded with 950 kg of explosives. The van was believed to be operated by members of ETA, a Basque nationalist group that had been engaged in an armed struggle for independence from Spain for decades. The explosives were intended for a large-scale attack on Torre Picasso, a prominent skyscraper and one of the tallest buildings in Madrid. This incident highlighted the heightened tensions in Spain concerning ETA's activities, which had seen a resurgence in violent actions during the late 1990s.

The operation to intercept the explosives was a critical success for the Spanish authorities, reflecting their ongoing commitment to combat terrorist threats. Authorities had received intelligence leading to the monitoring of the van's movements, enabling them to scramble and effectively neutralize the potential threat. This incident also raised public awareness about the persistent nature of ETA's violent campaign and the extensive risks that urban centers faced during this period.

The attempted attack on Torre Picasso symbolized a larger pattern of ETA's strategy to instill fear and assert their political agenda through violence. Furthermore, it showcased the urgent need for improved security measures and intelligence-sharing among European law enforcement agencies, especially in light of evolving terrorist tactics. In the weeks following the interception, debates surrounding counter-terrorism strategies intensified amongst government officials, security agencies, and the press.