Total war and political instability in the first half of the 20th century gave way to a polarized state order during the Cold War, and eventually to efforts at transnational union.
- World War I, caused by a complex interaction of long- and short-term factors, resulted in immense losses and disruptions for both victors and vanquished.
- The conflicting goals of the peace negotiators in Paris pitted diplomatic idealism against the desire to punish Germany, producing a settlement that satisfied few.
- In the interwar period, fascism, extreme nationalism, racist ideologies, and the failure of appeasement resulted in the catastrophe of World War II, presenting a grave challenge to European civilization.
- As World War II ended, a Cold War between the liberal democratic West and the communist East began, lasting nearly half a century.
- In response to the destructive impact of two world wars, European nations began to set aside nationalism in favor of economic and political integration, forming a series of transnational unions that grew in size and scope over the second half of the 20th century.
- Nationalist and separatist movements, along with ethnic conflict and ethnic cleansing, periodically disrupted the post–World War II peace.
- The process of decolonization occurred over the course of the century with varying degrees of cooperation, interference, or resistance from European imperialist states.
The stresses of economic collapse and total war engendered internal conflicts within European states and created conflicting conceptions of the relationship between the individual and the state, as demonstrated in the ideological battle among liberal democracy, communism, and fascism.
- The Russian Revolution created a regime based on Marxist–Leninist theory.
- The ideology of fascism, with roots in the pre–World War I era, gained popularity in an environment of postwar bitterness, the rise of communism, uncertain transitions to democracy, and economic instability.
- The Great Depression, caused by weaknesses in international trade and monetary theories and practices, undermined Western European democracies and fomented radical political responses throughout Europe.
- Postwar economic growth supported an increase in welfare benefits; however, subsequent economic stagnation led to criticism and limitation of the welfare state.
- Eastern European nations were defined by their relationship with the Soviet Union, which oscillated between repression and limited reform, until Mikhail Gorbachev’s policies led to the collapse of communist governments in Eastern Europe and the fall of the Soviet Union.
During the 20th century, diverse intellectual and cultural movements questioned the existence of objective knowledge, the ability of reason to arrive at truth, and the role of religion in determining moral standards.
- The widely held belief in progress characteristic of much of 19th-century thought began to break down before World War I; the experience of war intensified a sense of anxiety that permeated many facets of thought and culture, giving way by the century’s end to a plurality of intellectual frameworks.
- Science and technology yielded impressive material benefits but also caused immense destruction and posed challenges to objective knowledge.
- Organized religion continued to play a role in European social and cultural life, despite the challenges of military and ideological conflict, modern secularism, and rapid social changes.
- During the 20th century, the arts were defined by experimentation, self-expression, subjectivity, and the increasing influence of the United States in both elite and popular culture.
Demographic changes, economic growth, total war, disruptions of traditional social patterns, and competing definitions of freedom and justice altered the experiences of everyday life.
- The 20th century was characterized by large-scale suffering brought on by warfare and genocide as well as tremendous improvements in the standard of living.
- The lives of women were defined by family and work responsibilities, economic changes, and feminism.
- New voices gained prominence in political, intellectual, and social discourse.