Notes on the Spanish Military:

It's considerably more professional now that most of the old Francoists are long dead and the army is professional rather than conscript. It's still ungainly, though, and its role is not focused.

Spain has basically these military responsibilities, in approximately this order:

1. Do not allow Morocco to take over Ceuta, Melilla, and the Canary Islands.
2. (they can't say this out loud) Do not allow any attempt at revolt within Spain.
3. Fulfill its alliance with NATO and the United States.
4. Be useful in humanitarian efforts.
5. Participate actively in international military coalitions.

So here's what I'd do. I'd maintain "tripwire" forces in Ceuta, Melilla, and the Canaries. Morocco is not going to do anything silly, since its bilateral alliance with the US will restrain it, and all of NATO would come down on Morocco if that didn't work. But just in case everything goes to hell, Spain needs a small but elite, effective integrated air / naval / land force based somewhere in Andalusia that could be sent to any or all of these places in the event of a Moroccan attack. That takes care of responsibility number one, and this force might also be useful for responsibilities number three and five, assuming Spain only goes into such a coalition with the US and / or NATO.

Regarding responsibility number two, I would maintain a small, well-trained force of light infantry. These guys wouldn't be much good for combat, though they could fight if they had to; they wouldn't have very sophisticated weaponry, but they wouldn't need it because their real job is to suppress any uprisings that might happen in the Basque Country. The biggest pieces of weaponry they'd need would be Bradley light tanks, patrol helicopters, and ground-to-air missiles, and just a bare minimum of that. I would spend money and time training all of these guys as paramedics, truck drivers, military police, construction engineers, and communications / electronic pros. Then they'd also serve for responsibility number four, and they would be able to defend themselves though not mount any offensive operations; we can assume that Spain would be in no position to send out humanitarian aid if there were a real threat within the country.

Regarding responsibility number three, this one should not be where you spend your big money. There's no point in Spain possessing anything more than the bare minimum of planes and ships to patrol the areas around it in case US and NATO forces are needed elsewhere. Even if Spain spent jillions of euros, it could never catch up to American military competence, and since we have no evil imperialist plans to grab Algeria's natural gas or whatever, there's no point in even trying.