As promised, here are my thoughts on why Aznar stand side by side with Bush on his whole anti-terrorism war, ending with his support (but not active support, with spanish troops) on Irak war. It's not an original one, some of theseremarks has been published on spanish books or newspapers and spoken on radio-stations, but I'l try to get all the together.
The fist fact to take into account is terrorism. Aznar was a firm defessor of the idea (although it goverment was involved in arguments with terrorist group ETA while the tamp-letup the made, wich ended in the intent of ETA to bomb the "Torre Picasso" building in Madrid) that terrorism could only be fought with all the power of law and police. No dialogue could be made, and no illegal acts (as killing terrorists by GAL) could be enforced by government. There's little doubt that the fact that Aznar himself was the victim of a terrorist atack by ETA, in wich he barely survived by a matter of seconds, while he still was the head of opossition, marked his firm decission.
In old Europe, this was not clear: for them it was a domestic issue, and specifically France (although ETA claims part of their territory as an integral part of the Great Euskal-Herria, toghether with the whole Basque Autonomous Community and Navarra, wich is a Constitutional different Autonomous Country) has been a haven, together with some South-American countrys as Colombia, Cuba, and more recently Venezuela, for seeked terrorists.
Then it happened 9/11. As has been remarked by several goverment people, including Mariano Rajoy, PP's candidate to presidency who was the Internal affair Minister on that moment, the Bush resolution on war against terrorism and rogue countries made that EU arrived to some accords that were sought by Spain though decades in helping fight the terrorism: an euro-order of detention, an police efforcement, a transnational help on extradition of terrorism and so on. I think this was the first thing that make Aznar, together to a strong personal feeling with Bush, seek an active cooperation with America.
But the decissive fact was the invasion of the isle Perejil (Parsley in a plain translation) by Morocco on July 2002. On our history, the threat of muslim has been a constant for more than a thousand years, since the first conquest on 711 AD. Less than two years ago, they invaded this unhabited isle with ten soldiers, who planted the Marocco banner and stayed there. To me, it was a plain test to see if the could conquer the Spanish cities on Africa, Ceuta and Melilla, and futhermore the Canary Islands. As current dictator Mohammed parent, Hussein, did to the Sahara spanish territorry through the so called "Marcha Verde" (Green Walk) on the last years of franquism, he tried to see if spanish government was strong enough to fight back for their territories, or if the could begin again the conquest of the old Al-Landalus, following the word of the prophet.
Aznar turned to old Europe, and as answer, they turned their back. "Domestic affair". "Non EU businness". Same as balkans, same as always has been. Only Powell lifted the phone and backed Spain. Which were the allys? It's as clear to me as it was to Aznar.
Before and after Irak war, more signs of these appered on EU that streghtened Aznar possition (and also my own). The first one was the unilateral break of the non public deficit grow by France and German. Portugal had to pay fines for a lesser break a year ago, but no one was imposed on the old good Europe. The second one, the, again, unilateral refussal of France and Genmany to accept the Nice Treaty, signed by the whole EU, on where they established the voting proportions when the new members enter the EU. Their reasoning: it was too good for Spain. The signed it, but now it was too good for Spain.
A final remark on the spanish involvement on war. No spanish soldier participated on it. The troops arrived only after it finished.
Again, apologies for my poor english.