Domino theory (political)

The domino theory was a political idea during the Cold War suggesting that if one country in a region fell to communism, neighboring countries would likely follow, like a row of dominoes falling one after another. This theory justified efforts to prevent the spread of communism by intervening early in countries at risk, especially during the Vietnam War. It reflects concerns about regional stability and the idea that the fall of one nation could trigger a chain reaction, leading to widespread political change beyond the initial area.