What consequences resulted from the spread of nationalism during the 19th century and early 20th centuries

The spread of nationalism led to the rise of the patriotism in several countries that led them to form nation-states and fight against the colonial rule.

Explanation:

The rise of nationalism in Europe began to emerge during the French revolution, which introduced fraternity, equality and liberty. The French Revolution encouraged the people in Europe by forming the idea of patriotism. Nationalism emerged as a force in the 19th century, which gave changes in politics. These reforms resulted in the presence of the nation-states in place of the dynasty empires. Nationalism also led to the decline of the colonial rule in the world.

(APEX) - Colonized people in Africa and Asia began to launch independence movements.