The domino theory is a geopolitical theory that was prominent in the United States from the 1950s to the 1980s which posited that if one country in a region came under the influence of communism, then the surrounding countries would follow in a domino effect. The domino theory was used by successive United States administrations during the Cold War to justify the need for American intervention around the world.

Former U.S. President Dwight D. Eisenhower described the theory during a news conference on 7 April 1954, when referring to communism in Indochina as follows:

Finally, you have broader considerations that might follow what you would call the "falling domino" principle. 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.Moreover, Eisenhowers deep belief in the domino theory in Asia heightened the "perceived costs for the United States of pursuing multilateralism" because of multifaceted events including the "1949 victory of the Chinese Communist Party, the June 1950 North Korean invasion, the 1954 Quemoy offshore island crisis, and the conflict in Indochina constituted a broad-based challenge not only for one or two countries, but for the entire Asian continent and Pacific." This connotes a strong magnetic force to give in to communist control, and aligns with the comment by General Douglas MacArthur that "victory is a strong magnet in the East."

Dwight David "Ike" Eisenhower (born David Dwight Eisenhower; ; October 14, 1890 – March 28, 1969) was an American military officer and statesman who served as the 34th president of the United States from 1953 to 1961. During World War II, he served as Supreme Commander of the Allied Expeditionary Force in Europe, and achieved the five-star rank of General of the Army. He planned and supervised the invasion of North Africa in Operation Torch in 1942–1943 and the invasion of Normandy from the Western Front in 1944–1945.

Eisenhower was born into a large family of mostly Pennsylvania Dutch ancestry in Denison, Texas, and raised in Abilene, Kansas. His family had a strong religious background, and his mother became a Jehovah's Witness. Eisenhower, however, belonged to no organized church until 1952. He graduated from West Point in 1915 and later married Mamie Doud, with whom he had two sons. During World War I, he was denied a request to serve in Europe and instead commanded a unit that trained tank crews. Following the war, he served under various generals and was promoted to the rank of brigadier general in 1941. After the United States entered World War II, Eisenhower oversaw the invasions of North Africa and Sicily before supervising the invasions of France and Germany. After the war, he served as Army Chief of Staff (1945–1948), as president of Columbia University (1948–1953) and as the first Supreme Commander of NATO (1951–1952).

In 1952, Eisenhower entered the presidential race as a Republican to block the isolationist foreign policies of Senator Robert A. Taft, who opposed NATO and wanted no foreign entanglements. Eisenhower won that election and the 1956 election in landslides, both times defeating Adlai Stevenson II. Eisenhower's main goals in office were to contain the spread of communism and reduce federal deficits. In 1953, he considered using nuclear weapons to end the Korean War, and may have threatened China with nuclear attack if an armistice was not reached quickly. China did agree and an armistice resulted which remains in effect. His New Look policy of nuclear deterrence prioritized inexpensive nuclear weapons while reducing funding for expensive Army divisions. He continued Harry S. Truman's policy of recognizing Taiwan as the legitimate government of China, and he won congressional approval of the Formosa Resolution. His administration provided major aid to help the French fight off Vietnamese Communists in the First Indochina War. After the French left, he gave strong financial support to the new state of South Vietnam. He supported regime-changing military coups in Iran and Guatemala orchestrated by his own administration. During the Suez Crisis of 1956, he condemned the Israeli, British, and French invasion of Egypt, and he forced them to withdraw. He also condemned the Soviet invasion during the Hungarian Revolution of 1956 but took no action. After the Soviet Union launched Sputnik in 1957, Eisenhower authorized the establishment of NASA, which led to the Space Race. He deployed 15,000 soldiers during the 1958 Lebanon crisis. Near the end of his term, he failed to set up a summit meeting with the Soviets when a U.S. spy plane was shot down over the Soviet Union. He approved the Bay of Pigs Invasion, which was left to John F. Kennedy to carry out.

On the domestic front, Eisenhower was a moderate conservative who continued New Deal agencies and expanded Social Security. He covertly opposed Joseph McCarthy and contributed to the end of McCarthyism by openly invoking executive privilege. He signed the Civil Rights Act of 1957 and sent Army troops to enforce federal court orders which integrated schools in Little Rock, Arkansas. His largest program was the Interstate Highway System. He promoted the establishment of strong science education via the National Defense Education Act. His two terms saw unprecedented economic prosperity except for a minor recession in 1958. In his farewell address to the nation, he expressed his concerns about the dangers of massive military spending, particularly deficit spending and government contracts to private military manufacturers, which he dubbed "the military–industrial complex". Historical evaluations of his presidency place him among the upper tier of American presidents.