When Eisenhower used the phrase the domino theory what did he mean?

"You have a row of dominoes set up, you knock over the first one, and what will happen to the last one is a certainty that it will go over very quickly." This would lead to disintegration in Southeast Asia, with the "loss of Indochina, of Burma, of Thailand, of the Peninsula, and Indonesia following." - Eisenhower speech April 7, 1954 .
US President Dwight Eisenhower referred to the "Domino Theory" meaning if the US did not stop the spread of communism then , by inference , the US would eventually be fighting the communists on US soil . He made the analogy as a way of garnering support for the fight against communist expansionism . He felt that if South Vietnam fell to the communists then the next nation would be Cambodia , then Laos , then Thailand , etc...