The Spanish conflict generated the most intense propaganda struggle of all the European civil wars, even more than the one in Russia. The latter had been covered extensively by the print media, but took place in a distant and exotic country that was hard to reach at the conclusion of World War I. Even if the complexity of its politics was little understood, Spain was more accessible in every way: geographically, culturally, and technologically. In the fifteen years since the end of the Russian war, the print media had expanded considerably and what some call the golden age of the foreign correspondent had begun. By comparison, correspondents had been rare in Russia, whereas the latest media, such as radio and the cinema, were much more developed in the 1930s. No other civil war became a war of propaganda and culture to an equivalent extent, not merely because of the dramatic revolutionary confrontation and the growing shadow of international power politics in the war itself, but also because of the character and conflicts of contemporary culture as they interacted with the Spanish war.

Both sides not only made major efforts to develop propaganda and cultural resources within their own zones, but also to appeal to opinion abroad. Here the left enjoyed certain advantages, based on mobilized political organizations, to which were added the formidable facilities of the Comintern. The Nationalists, by contrast, began with an improvised military regime lacking equivalent resources, and were slower to develop their own facilities. In the long run, this struggle would be won by the left, whose version of the Spanish conflict would be the one most frequently repeated in later years. Yet during the war itself, the Nationalists won the more narrow battle to influence decisive political opinion abroad, concentrating on conservative political and religious sectors, particularly in Britain and France, and to a somewhat lesser degree in the United States.