Before the Great War of 1914–18 ended, the successor states of four Eurasian empires split into conservative, liberal and revolutionary camps; ideological battles that had been waged for nearly a century were resumed like trench warfare in the streets of cities, in diplomatic salons, in the pages of broadsheets and in parliamentary halls. By the middle of the 1930s these ideological battles had again brought forth a civil war, this time in Spain, which came as an augury, tragic and bloody, conjoining the past, present and future in a grim garden of forking paths. This was the setting after the Second World War in which some western European nations sought to lay the basis for what would come to be called ‘an ever closer union’, whilst a rather different ‘union’ settled upon their eastern neighbours under Soviet rule. The processes of unification in eastern and western Europe were reactions and stimuli to the diminution of European power during the post-war period.