 On 18 June 1954 , Castillo Armas led a convoy of trucks carrying 480 men across the border from Honduras into Guatemala . The weapons had come from the CIA , which had also trained the men in camps in Nicaragua and Honduras . Since his army was badly outnumbered by the Guatemalan army , the CIA plan required Castillo Armas to camp within the Guatemalan border , while it mounted a psychological campaign to convince the Guatemalan people and government that Armas ' victory was a fait accompli . This campaign included using Catholic priests to give anti @-@ communist sermons , strafing several towns using CIA aircraft , and placing a naval blockade around the country . It also involved dropping leaflets by airplane through the country , and carrying out a radio broadcast entitled " The Voice of Liberation " which announced that Guatemalan exiles led by Castillo Armas were shortly about to liberate the country . 
