At the Fourteenth Party Congress, in 1925, against the protests of Trotsky and others, the party performs a giddying about-face. Now it officially accepts Stalin’s claim that ‘in general the victory of socialism (not in the sense of final victory) is unconditionally possible in one country’. The parenthetical caveat notwithstanding, the embrace of ‘Socialism in One Country’ is a dramatic reversal of a foundational thesis of the Bolsheviks – and others.