Spain's sudden change might be a good one for the country as an individual nation, but that's still only a 'might' and definitely isn't good for the global community. It's like when Hitler was appeased before WWII. While they may have obtained relief from Al Qaeda, they are just letting the Basque terrorists that are indiginous know that if they kill enough people they can get what they want. Similarly, Al Qaeda has gotten a boost by setting out to do a mission having its goal fully accomplished; I'm sorry that all those people in Spain died, but I'm also sorry about the response to it.