United States President Dwight D. Eisenhower gives his “domino theory” speech during a news conference.

Dwight D. Eisenhower was the 34th President of the United States, serving from 1953 to 1961. In 1954, during the early years of the Cold War, he delivered a speech in which he articulated what would come to be known as the “domino theory.”

The speech was delivered on April 7, 1954, at a press conference in Washington, D.C. Eisenhower was responding to a question about the situation in Indochina, where the French were fighting a war against communist forces in Vietnam. The president expressed concern that if Vietnam were to fall to communism, it would set off a chain reaction in Southeast Asia and beyond.

Eisenhower said: “You have a row of dominoes set up, you knock over the first one, and what will happen to the last one is the certainty that it will go over very quickly. So you could have a beginning of a disintegration that would have the most profound influences.”

The “domino theory” was a metaphor for the idea that if one country in a region were to fall to communism, neighboring countries would be at risk of falling as well, creating a chain reaction that could ultimately lead to the spread of communism around the world. The theory was used to justify U.S. involvement in the Vietnam War, as the U.S. sought to prevent the spread of communism in Southeast Asia.

The domino theory became a controversial concept, and some critics argued that it was an oversimplification of the complex political and economic factors that influenced the spread of communism. However, the theory remained influential in U.S. foreign policy for several decades, shaping U.S. intervention in conflicts in Korea, Vietnam, and other parts of the world.