The inter-war period revealed the fragility of European liberal democracies. In this paper, using the customary comparative approach, the author focuses in particular on the role played by fascism and radical nationalism in the weakening of the idea and practices of democracy. Indeed, even when the advocates of these ideologies did not manage to come to power, they nevertheless generated sufficient fear, hatred and threat to public order such that the utopia of progress so dear to political liberalism was called into question.