Due to exhaustion from battling each other in the World Wars I and II, European countries were losing their colonial empires. Between 1945 and 1960, three dozen new states in Asia and Africa achieved autonomy or outright independence from their European colonial rulers.
There was no one process of decolonization. In some areas, it was peaceful, and orderly. In many others, independence was achieved only after a protracted revolution.
A few newly independent countries acquired stable governments almost immediately; others were ruled by dictators or military juntas for decades, or endured long civil wars.
Some European governments welcomed a new relationship with their former colonies; others contested decolonization militarily.
During World War II Japan, itself a significant imperial power, drove the European powers out of Asia. After the Japanese surrender in 1945, local nationalist movements in the former Asian colonies campaigned for independence rather than a return to European colonial rule. See more at History.State.gov - Decolonization of Asia and Africa, 1945–1960.
Check out Study Tips for Social Studies including History & Geography from BreakthroughLearninghs.com.