Two causes of the rise of dictatorships after world war i were

After world war dictators started to rule the major European countries, Stalin in Russia, Mussolini in Italy and Adolf Hitler in Germany. The reason for their rise was that all of them were unhappy with the outcomes of the war. Mussolini's rise was related to the Treaty of Versailles. since the Italians hadn't benefited from the war and the war had disrupted its economy, it made it easy for the Fascists to come to power by using propaganda.

In the case of Germany also the Treaty of Versailles was the main reason. The war guilt clause was big trouble for Germans and Hitler used it to capitalize on the emotions. The rise of Stalin in Russia was directly related to world war. The war exposed the weakness of the Czarist monarchy and made the Bolshevik victory possible and later after the death of Lenin, Stalin became the supreme leader of the USSR.

Use of propaganda was also equally important factor. As the democracy weakened in these countries, such personalities assured people that totalitarian regimes were the solution to all the post war problems.