The Domino Theory was a political theory popular during the Cold War era, particularly in the 1950s and 1960s. It posited that if one country in a region came under communist control, neighboring countries would also fall to communism, like a row of falling dominoes. This theory was used to justify American involvement in various conflicts, particularly in Southeast Asia, such as the Vietnam War. The fear was that if one country, such as Vietnam, fell to communism, it would create a ripple effect and lead to the spread of communism throughout the region, threatening US interests. The Domino Theory was eventually discredited as the Vietnam War escalated and ended in a stalemate, leading to a reevaluation of US foreign policy.
