An excellent Weekly Standard editorial:

Outgoing Spanish prime minister José María Aznar made the decision to back the United States in its war on terror, not just in Afghanistan but also in Iraq. In the face of significant political resistance, he reached the assessment that seems to us the correct one: September 11 was Spain's September 11. In the same way, March 11 is our March 11. It confronts the United States with similarly solemn obligations of unlimited solidarity, not just in words but in deeds.