The United States was not a colonial power in the early 20th century, while France, Germany, and Italy were.

The main reason for the European powers to colonize Africa and Asia was to gain access to natural resources, such as minerals, oil, and rubber.

Great Britain had the largest colonial empire in the world in 1914, with colonies in Africa, Asia, and the Americas.

Colonialism contributed to the outbreak of World War I in a number of ways, including creating tensions between the European powers, leading to the rise of nationalism in the colonies, and causing economic instability in Europe.

The Battle of Gallipoli was a major battle of World War I that took place in a colonial territory, specifically the Gallipoli Peninsula in the Ottoman Empire.

Colonialism contributed to the outbreak of World War II in a number of ways, including creating tensions between the European powers, leading to the rise of fascism in Europe, and causing economic instability in Europe.

The Battle of El Alamein was a major battle of World War II that took place in a colonial territory, specifically Egypt, which was a British colony at the time.

Colonialism affected the course of World War II in a number of ways, including providing the Axis powers with resources and manpower, weakening the Allied powers, and leading to the rise of anti-colonial movements.

All of the above were major anti-colonial movements that emerged during World War II.

Colonialism contributed to the decolonization process after World War II in a number of ways, including weakening the European powers, leading to the rise of nationalism in the colonies, and causing economic instability in Europe.

All of the above countries gained independence from colonial rule after World War II.

Colonialism affected the development of the global economy in the 20th century in a number of ways, including leading to the rise of global capitalism, creating a system of economic inequality, and causing economic instability in Europe.

Colonialism had a negative impact on the environment in the 20th century, leading to deforestation, soil erosion, and pollution of the air and water.

Colonialism contributed to the spread of Western culture and values around the world in a number of ways, including leading to the spread of Christianity, introducing Western education and technology, and promoting Western political and economic ideas.

The legacy of colonialism in the 20th century was complex and multifaceted, including leading to the rise of nationalism in the colonies, creating a system of economic inequality, and causing environmental degradation.