Timeline of United States military operations communist attack on a U.S. installation in central Vietnam, the United States escalated its participation in the war to a peak of 543,000 military personnel by April 1969. 1961: Cuba: The Bay of Pigs Invasion, known in Hispanic America as Invasión de Bahía de Cochinos (or Invasión de Playa Girón or Batalla de Girón), was an unsuccessful military invasion of Cuba undertaken by the CIA-sponsored paramilitary group Brigade 2506 on April 17, 1961. 1962: Thailand: The Third Marine Expeditionary Unit landed on May 17, 1962 to support that country during the threat of Communist pressure from outside; by July 30,
CIA activities in Vietnam had difficulties understanding their politics. This can be attributed to the fact that the CIA did not make a concerted effort to gain a better understanding of the history and people of Vietnam. The CIA instead focused on the military forces occupying the territory instead of the political and economic forces that motivated them. The diplomats were not getting clear information in 1954 and early 1955, but the CIA station "had ... no mandate or mission to perform systematic intelligence and espionage in friendly countries, and so lacks the resources to gather and evaluate the large amounts of information required