Here's an article by Stanley G. Payne in Spanish about what the declassified Soviet archives let us know about the Spanish Civil War. He says that one thing that surprised him is that these internal Soviet documents is that they used the same "running-dog-hangman-butcher-paid-agent-Trotskyist" rhetoric as they used to the public. He also says, "The dictator who took best advantage of the war was not Stalin but Hitler, since the objective of the Nazi leader was not so much to contribute to a rapid Franco victory, but to prolong the conflict as long as possible in order to distract attention from German rearmament and German expansion in Central Europe, dissuade the democratic countries, create internal divisions in France, and involve Mussolini in German plans. In each of these aspects Hitler was entirely successful."
Here's Payne's introduction to a University of Wisconsin (where he is Hilldale-Jaume Vicens Vives Professor) exhibition called Life under Italian Fascism. You really ought to take a look at the whole exhibition. This is a chapter from one of Payne's books on the formation of Portugal. Uh, duh, my bad, here's the whole damn book, titled "A History of Spain and Portugal". It runs through the end of the 1600s.