The primary cause of the rise of **fascism** in Europe during the early 20th century was widespread discontent following **World War I** and the **Treaty of Versailles**, which imposed harsh reparations and territorial losses. Economic instability, coupled with high unemployment and political turmoil, created fertile ground for authoritarian ideologies. Fascist leaders promised a restoration of national pride, social order, and economic recovery. Utilizing propaganda and nationalist sentiment, movements in countries like **Italy** and **Germany** gained traction, ultimately leading to oppressive regimes that suppressed dissent and embarked on aggressive militarism, reshaping European political landscapes.