Final answer:
Authoritarian regimes after World War I rose to power by exploiting economic and political instability, promising national rejuvenation and providing basic needs. They maintained power through totalitarian control, nationalism, propaganda, violence, and suppression of dissent. The regimes' ideologies, such as fascism, also played a crucial role in their consolidation of power.
Step-by-step explanation:
After World War I, authoritarian and dictatorial regimes emerged across Europe during a time of significant economic turmoil and political instability. These regimes, which included fascist dictatorships, gained power by capitalizing on the despair and discontent of the population who were suffering from the war's aftermath. Leaders like Benito Mussolini in Italy and Adolf Hitler in Germany promised jobs, food, and a return to national glory, which appealed to the masses. Once in power, they maintained their grip through tactics such as aggressive nationalism, propaganda, systemic violence, and the suppression of opposition, which fostered a climate of fear.
Totalitarianism, characterized by the control of every aspect of life, both public and private, became the reality as laws changed frequently, and individual identity was subsumed under the collective identity of the state. Leaders such as Joseph Stalin in the Soviet Union leveraged collectivization and the nationalization of economic resources to consolidate power. In effect, the interwar period saw the cultivation of total terror as a means of control.
The ideology of fascism, with its disdain for democratic principles and belief in social hierarchy, further supported such regimes in acquiring and maintaining power. The expansion of territory was a key facet for these dictatorships, as it tied in with nationalist sentiments and the pursuit of resources and prestige. The support of the military and the creation of state-operated economies also reinforced their power structures.