Domino theory

The domino theory is an idea that says if one country becomes more or less democratic, it can affect nearby countries like a chain reaction. 

This theory was important in the United States from the 1950s to the 1980s during the Cold War. It suggested that if a country in a region turned communist, then the countries around it would also become communist. 

The U.S. used this theory to justify getting involved in different parts of the world. President Eisenhower talked about it in 1954, comparing it to knocking over a row of dominoes. He believed that if one country fell to communism, others nearby would quickly follow. This belief in the domino theory influenced U.S. decisions in Asia during the Cold War, making them more focused on stopping communism to prevent a chain reaction of countries becoming communist.

Category:20th century in the United States