The Spanish government can brush off a history book and read how the British Parliament reacted to the Boston Tea Party. Maybe they can close the port of Barcelona until the Catalans come to their senses.
Barcelona IS the Spanish economy. It's actually the 4th largest city economy in the EU.
And that's the problem, they're carrying the rest of the country and Madrid gets the fancy upgrades.
Well Spain doesn’t need to look that far back.
In the 30s they just besieged the place until the people there gave in.