1954 in the Vietnam War 5 April The National Security Council met again to consider U.S. intervention at Điện Biên Phủ. The Army, including Army Chief of Staff General Matthew Ridgway, was negative, stating that U.S. intervention would require 7 army divisions and heavy air support. 7 April President Eisenhower used the phrase "falling dominoes" in a press conference. This was the origin of the domino theory which postulated that if Vietnam became communist the other nearby states would soon follow. The domino theory was a prominent justification for the Vietnam War in the United States during the 1960s. 14 April Secretary of State John
Sovereignty of Puerto Rico during the Cold War in the onset of World War III in October 1962. Afterwards, the United States hardened its influence throughout Latin America, involving itself in what became known as the "Dirty War", a process that involved questionable actions including supporting or overthrowing governments depending on political leaning, supporting subversive groups such as the Contras with weaponry and funding, or participating in controversial operations such as Operation Charly and Operation Condor. The fallout from these actions affect Latin America–United States relations to this day. Having been annexed from Spain in 1898, the unincorporated territory of Puerto Rico represented a paradox during the Cold