What Is Unit 9 About in AP World History?

Unit 9 of the AP World History curriculum covers the period of global conflict and change from 1900 CE to the present day. This unit encompasses a vast range of events, including world wars, decolonization, globalization, and technological advancements. Let’s take a closer look at what this unit is all about.

The World at War

The first part of Unit 9 focuses on the two World Wars that defined the twentieth century. During this time, major powers such as Germany, Japan, and the United States fought for dominance on multiple fronts. The impact of these wars was felt worldwide and led to significant political and economic shifts that continue to shape international relations today.

Decolonization and Nationalism

As the world emerged from the chaos of war, many nations sought to gain independence from their colonial rulers. The process of decolonization was often fraught with conflict as new nations struggled to establish their own identities in a rapidly changing world. Nationalism also played a significant role during this time as people sought to assert their cultural and political identities in an increasingly interconnected global community.

Globalization and Interconnectedness

In recent decades, globalization has become a defining feature of our world. Advances in technology have made it easier than ever before to connect with people from all over the globe.

At the same time, economic integration has led to unprecedented levels of trade between nations. While globalization has brought many benefits, it has also created new challenges such as income inequality and environmental degradation.


Unit 9 is a crucial part of the AP World History curriculum as it covers events that have shaped our modern world. From world wars to decolonization and globalization, this unit explores how human society has evolved over time in response to changing political and economic realities. By studying these events, students gain a deeper understanding of the complex forces that have shaped our world and the challenges we face today.