I know this must seem like a superwise sage reply to you, but the truth is that if Spain does not face threats they cannot counter via pursuing their own alliances and spending <5% of their GDP (a very substantial sum), the ask is a bad deal .
It's amazing how common this *genuinely stupid* take is. Like a shepherd not seeing why he should have to fork out for the annual wolf hunt because he hasn't lost any sheep to wolves in ages.