Julián Casanova in Eurozine:
In the first few months of 1936, Spanish society was highly fragmented. There was uneasiness between factions and, as was happening all over Europe with the possible exception of the United Kingdom, the rejection of liberal democracy in favour of authoritarianism was rife. None of this need have led to a civil war. The war began because a military uprising against the Republic undermined the ability of the State and the Republican government to maintain order. The division of the army and security forces thwarted the victory of the military rebellion, as well as their main objective: the rapid seizure of power. But by undermining the government's ability to keep order, this coup d'état transformed into the unprecedented open violence employed by the groups that supported and those that opposed it. It was July 1936 and thus began the Spanish Civil War.
The civil war came about because the military coup d'état failed to achieve its basic objective at the outset, which was to seize power and overthrow the republican regime, and because, unlike the events in other republics of the time, there was comprehensive resistance, both military and civil, to counter any attempt at imposing an authoritarian system. Had it not been for this combination of coup d'état, division of the armed forces and resistance, there would never have been a civil war.
This coup d'état met resistance because the Spanish society of 1936 was not the same as that of 1923, when the September uprising led by General Miguel Primo de Rivera was favoured by the general abstention of the army, the weakness of the government, the apathy of public opinion and above all, the consent of King Alfonso XIII.
In 1936 there was a Republic in Spain, whose laws and measures had given it the historical opportunity to solve insurmountable problems, but it had also come across, and caused, major factors of instability, which successive governments could not provide the proper resources to counteract. Against such a widespread level of political and social mobilization as had been set in motion by the Republican regime, the coup d'état could not end, as had occurred so many times in Spain's history, in a mere return to the old order, based on traditional values. To overthrow the Republic, what was needed was a new, violent, antidemocratic and antisocialist order, such as had previously been established elsewhere in Europe, to end the crisis and repair all the fissures that had been opened, or widened, by the Republican regime.