Why was Franco exhumed from the Valley of the Fallen in late 2019? How is it that he was there in the first place? Why did Catalonia erupt suddenly in October 2017? Why don't you hear so much about the Basque Country anymore? How did Podemos gather momentum so quickly in 2014-15, and why did half of that support vanish five years later? Isn't it counterintuitive that a Catholic-majority country also has the most LGBT-friendly society in the world?

Understanding the most significant events in recent Spanish politics requires spelling out the unspoken but enduring foundations of the country's deepest fears and weaknesses, its Achilles' heels. In Greek mythology, an Achilles' heel is a vulnerability that can lead to downfall despite the apparent general strength of the full body. Casla uses this term to define the underlying factors that, while by no means unique, are characteristic of a particular society, delimit what is possible and shape the political debate. They are the primary political frailties without which a country's politics cannot be properly comprehended.