Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum

Monthly Update sign up
Mailing List signup
Unit Home
Unit Content Overview
References & Sources
Unit Audio Glossary
Related Units

UNIT 22: Global War and Peace



World history is full of conflicts that pitted people against people, nation against nation, or region against region. In the eighteenth and nineteenth centuries, wars of conquest or liberation pitted colonies against their colonial overlords, or they drew imperial powers into battle against one another for control of distant lands and peoples.

In the twentieth century, however, the arrivals of modern technologies of transportation, power, and communication made such conflicts distinctive in size, scope, and conduct. They brought people, weapons, and interests from the furthest corners of the globe onto European soil; they pushed European conflicts to the edges of the earth. Battles and conflicts erupted in Europe, Africa, Asia, and the Americas on an entirely new scale-with bigger ships, deadlier weapons, and the faster transportation of troops.

This unit examines the costs and consequences of twentieth-century global conflicts. In terms of human lives lost and resources spent, these conflicts remain unparalleled in the history of the world. Yet they also ultimately gave voice — and some new measure of control and self-definition-to peoples previously excluded from world politics. Indeed, by the end of the century, independent nations in Asia, Africa, and the Pacific that had once been colonies were — to a greater extent than ever before — independent actors on the world stage. Their voices were critical in arguing for the recognition of universal human rights on a global basis.

At the same time, and partly as a result of the legacies of imperialism, these same new nations were also freer to emphasize distinctions of race, nation, religion and region in domestic and international relations. Even as post-war global governing bodies like the United Nations were founded to mediate disputes over these issues, nationalism, regionalism, and racism increasingly threatened to tear the fragile world peace apart again.


Time Period: Twentieth century

War was a recurring feature of the twentieth century, whether those wars were regional and spatially limited or global in scale. Humanity's two bloodiest and most costly wars occurred in this century-World War I and World War II-and in spite of international peace organizations, war continued to devastate human populations after 1945 as well. Some twentieth-century wars were exacerbated by the United States' and the Soviet Union's interventions between 1945 and 1989, as both nations vied for the allegiances of lesser powers during the Cold War. Other wars were triggered by independence movements in regions trying to break free of colonial domination after World War II. Many of these movements were ultimately successful, and during the 1950s and 1960s most of the world was decolonized. Increasing integration and globalization during the twentieth century produced an atmosphere that lent itself to international and regional conflict, while it also provided unique opportunities for international cooperation in the search for peace.

AP Themes:

  • Examines interactions in economies and politics by exploring international war and peace in the twentieth century, and by looking at the ways both facilitated connections between the world's peoples.
  • Explores technology, demography, and environment through a look at the ways twentieth-century war-the scale of which was made possible by technological advances in transport and weaponry-changed and often destroyed human populations and the natural environment.
  • Discusses changing functions of states by focusing on how the post-World War II political climate dictated the needs for international and transnational organizations such as the United Nations.


  • Question 1: How did global warfare in the twentieth century differ from previous conflicts?
  • Question 2: What were some of the global consequences of the twentieth-century World Wars?
  • Question 3: How did global capitalism and political changes in both Europe and Asia help give rise to global warfare in the twentieth century?
  • Question 4: How did imperialism help to create the conditions for global war in the twentieth century, and what effects did those wars have on empires and colonies in both the short and long terms?


How is this topic related to Increasing Integration?

The experience of war in the twentieth century integrated many parts of the world. People were brought together ideologically across vast spaces to fight forcommon causes; economically as a result of wartime needs for resources and products; and in battle as people from all over the world served as soldiers and laborers.

How is this topic related to Proliferating Difference?

Global warfare in the twentieth century was caused by-and led to a heightened awareness of-differences between peoples, whether those differences were racial, national, ethnic, or ideological.

Back to Top


© Annenberg Foundation 2017. All rights reserved. Legal Policy