First, when the Nationalist coup failed to unseat Spain's People's Front government in 1936, the rest of Western democracies (notably the US, UK and France) declared themselves neutral and the League of Nations enforced an arms embargo on Spain which Hitler and Mussolini dutifully ignored. That threw the Spanish Republic in the hands of Stalin, who was all too happy to have the Communist-controlled Republican Army fight the Anarchist militias and the Socialist government as much as they fought the Fascists. By the way, this is the reason why I was opposed to the international Arms embargo during the Yugoslav civil war, but that's another story.
Then, the Spanish Republican Refugees were treated like shit by France after their defeat (basically penned in concentration camps), and corresponded by dutifully fighting for the Free French and helping the Allies mop up the Germans after D-Day. They must have hoped that Franco would be taken on after Hitler and Mussolini, but it was not to be.
Finally, as the war was coming to an end Franco's anticommunism outweighed his Fascism in the eyes of the Allies, who were already preparing for the Cold War. So, the Spanish Republicans had to content themselves with lobbying to keep Spain out of the UN, and they succeeded until about 1955, when Eisenhower visited Spain to welcome Franco into the "Free World". Too bad the Spanish people had to wait until the death of the Dictator to free themselves.
Then Spain, was allowed to send its people to Europe as guest workers to fuel the German Miracle, and opened up to tourism in the 1960's. So not only did Spain have to endure 10 years of isolation but we also missed out on the Marshall Plan. Just in case you wonder why Spain and Portugal are so far behind the rest of Western Europe economically.
So, yeah, we're very grateful. tens of millions of people stand to see their lives ruined because the bureaucrats at the ECB don't understand introductory economics -- Dean Baker