Are you sure about that? My understanding is that Trump wanted individual agreements agreements between countries and not "blocks".
I just don't know, but I don't see the EU stepping up to defend Spain since all of them are supporting full NATO funding. They will not be happy picking up Spain's bar tab.
It doesn’t matter what Trump thinks they are all part of the same single market and customs union. You cannot tarrif one member state without tarrifing all of them and you are not going to persuade them to break ranks with Spain and thus totally unravel their ability to negotiate trade agreements with the US at peer level vs individual countries with inferior leverage.