Answer: The domino theory was a Cold War policy that suggested a communist government in one nation would quickly lead to communist takeovers in neighboring states, each falling like a perfectly aligned row of dominos. ... With the exception of Laos and Cambodia, communism failed to spread throughout Southeast Asia
Explanation: The basic idea was that the American's needed to prevent the first domino from falling (country turning to communism) in order to prevent the spread of communism. ... For example, the domino theory was used to justify American involvement in both the Korean War and Vietnam War from the 1950's to the 1970's.
