The Cold War essentially changed the way that people view other countries and how to approach future conflicts. In America, during the Cold War the Red Scare led many people to be against immigrants and other ideologies such as communism. There was also the threat of a Nuclear War between the Soviet Union and the US. Where both sides were forced to not fight because if they did the end of the world would ensue. Many countries were overtaken by the Soviet Union leading to them becoming communist countries as well.
The colonies suffered badly during the Depression of the 1930s. The imperialist European countries had encouraged their colonies to produce raw materials for European factories.