The radical leftist politics of his literary friends, as well as that of del Carril, were contributing factors, but the most important catalyst was the execution of García Lorca by forces loyal to the dictator Francisco Franco.
Hans litterära vänners radikala vänsterengagemang, liksom del Carril, var bidragande faktorer, men den viktigaste orsaken var avrättningen av García Lorca av styrkor lojala till Francisco Franco.