Answer:
Domino Theory
Explanation:
The Domino Theory referred to the idea that if a country became communist, neighboring countries would become communist too, in a more or less short time frame.
The name from the theory comes from the fact that when dominoes are arranged vertically, if one domino falls down, all the other fall down as well.
The Domino Theory was one of the basis for the Vietnam War. The American leadership believed that if Vietnam became communist, neighboring countries such as Laos, Thailand or Malasya would soon become communist too.
In the end, the Domino Theory did not prove fully correct. For example, while Laos did become communist soon after, niether Thailand nor Malasya became so.
