The rise of nationalism: World War II also led to the rise of nationalism in many colonized countries. This was due in part to the fact that many colonized peoples had fought alongside their European colonizers during the war, and they began to feel that they deserved the same rights and freedoms as their European counterparts.
The Cold War: The Cold War between the United States and the Soviet Union also played a role in the decline of European colonialism. The two superpowers competed for influence in the developing world, and they often supported nationalist movements in order to weaken their rivals. This further accelerated the process of decolonization.
By the end of the 1960s, most European colonies had gained independence. The few remaining colonies, such as Hong Kong and Macau, were eventually returned to their respective countries in the 1990s.