Also, there was a fairly wide range of parties that were on the Republican side during the Spanish Civil War. The communists ended up being the strongest, and gaining control on the republican side, but that was not always certain. There is some merit to the idea that if the Republican side had managed to agree for longer, they could have beat Franco. Although the question of if the internation community would ahve allowed this to happen remains open. The communist party was also likely taking its orders from Moscow, and it was not in the best intrests of Moscow to see Spain become an independent, truly communist country.
My opinions, based on limited knowledge of the situation, and mostly on reading "Homage to Catalonia" by Orwell. This is an excellent and very readable personal account of the war and politics on the Republican side.
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