In this episode, we unpack the "domino theory," a defining geopolitical concept of the 20th century which posited that if one country fell to communism, its neighbors would inevitably follow in a chain reaction. We trace the theory's origins from President Harry S. Truman’s aid to Greece and Turkey to its popularization by President Dwight D. Eisenhower in 1954, who famously warned that knocking over the first "domino" in Indochina would lead to widespread disintegration,.

We discuss how this metaphor became the primary justification for U.S. intervention in Vietnam under the Kennedy and Johnson administrations,. The episode examines historical arguments supporting the theory, such as the 1975 communist takeovers of South Vietnam, Laos, and Cambodia, as well as the counter-evidence, including the CIA’s skepticism in the 1960s and the failur ...