2004 – Madrid Train Bombing
On March 11, 2004 an al-Qaeda-inspired terrorist cell coordinated bombings in the Madrid commuter train system. The bombs were detonated in the morning of March 11, killing 191 people and wounding 1,800. While no direct link between the group and al-Qaeda was found, the attack heightened fear and anxiety surrounding al-Qaeda activity.
To learn how these attacks affected US policy, check out this CRS (Congressional Research Service) report from the HSDL collection: March 11 Terrorist Attacks in Madrid and Spain’s Elections: Implications for U.S. Policy [October 5, 2004]