The war had caused widespread damage and disruption, and many countries were struggling to rebuild. This led to high levels of unemployment, inflation, and poverty. These conditions made it difficult for democratic governments to function effectively, as they were unable to meet the needs of their citizens.
In addition, many European countries were dealing with the rise of nationalism and fascism. These ideologies offered simple solutions to the complex problems that these countries were facing, and they appealed to many people who were feeling frustrated and disillusioned with democracy.
As a result of these factors, democratic governments failed in many European nations after World War I. In some cases, they were replaced by authoritarian regimes, while in others, they were replaced by communist governments.