
On this day in 1954, American president Dwight D. Eisenhower – a war hero and mastermind of the invasion of occupied France – explained what would become known as the Domino Theory during a routine press conference. China, a newly-communist power, was increasingly threatening American interests in Asia; after the Korean War, North Korea represented another regional challenge. As the French struggled against communist forces to retain control of Vietnam (or, French Indochina), the American president became increasingly worried that a chain reaction had been set in motion that would result in an exponential growth of communist power in the region, and the world at large. Explaining his concerns, Eisenhower reminded listeners that…
“…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.”
President Dwight D. Eisenhower

Informed by his experiences of rapid Axis territorial gains during WWII, Eisenhower believed that small and seemingly “insignificant” countries could be infiltrated by propaganda and militia movements from neighbouring communist countries. In this way, Chinese communists (backed by the USSR) had provided military support to North Korea; if Vietnam fell to the communist Viet Minh, Eisenhower feared, that power would influence neighbouring countries like Laos and Cambodia which, with their precarious economic situations, were vulnerable to the appeal of communism. Whatever the merits or drawbacks of Eisenhower’s prediction, the Domino Theory played an important part in informing American and NATO policy for the duration of the Cold War and justifying military interventions in smaller, poorer countries, like the ensuing Vietnam War.