A once-secret CIA history of the Bay of Pigs invasion lays out in unvarnished detail how the American spy agency came to the rescue of and cut deals with authoritarian governments in Central America, largely to hide the U.S. role in organizing and controlling the hapless Cuban exile invasion force.

The report, in chronicling how American secret agents dealt with the ’60s-era governments of Guatemala and Nicaragua, provides important evidence, in official U.S. government words, to the truth of the old adage that the most powerful people in Central American embassies were the CIA station chiefs.

Ambassadors step aside and allow the CIA to negotiate deals for covert paramilitary bases in a newly released portion of the CIA’s “Official History of the Bay of Pigs Operation.” CIA pilots and Cuban foot soldiers then help suppress a Guatemalan Army coup attempt that threatened their foothold in the country. Gen. Anastasio Somoza hits up the CIA for a $10 million payoff, development loans, as the price of letting the Americans launch the Cuban exile invasion from Nicaragua.

“What you’re reading in this report shows again that in the hypocritical name of democracy the United States and CIA were willing to prop up some of the most cut-throat dictatorships,” says researcher Peter Kornbluh of the National Security Archive at George Washington University. He sued the CIA for release of the Top Secret document that dissects one of the agency’s greatest failures.

Using secret interviews, cables and memos, CIA historian Jack B. Pfeiffer wrote the classified account of the disastrous operation to topple Fidel Castro. It’s unusually candid because nobody except spies were expected read it.

Volume II, just released, focuses on foreign policy, particularly dealings with Guatemala and Nicaragua. It struck Kornbluh as a surprisingly “self-complimentary description of the CIA’s agile role as a diplomatic force.”

Both the Eisenhower and Kennedy governments wanted to be able to deny responsibility for the invasion. So the bulk of the paramilitary training took place in Guatemala, with hundreds of anti-Communist Cuban foot soldiers and their CIA trainers packed away for months on a remote ranch. Nicaragua would later provide the runway and launch site for the actual air and sea operation.

But Guatemala was formative. So much so that the Cuban exile force’s Brigade 2506 got its name there when a trainee fell of a cliff and plunged 6,000 feet to his death. Carlos Rodriguez was the first to die in the fiasco, seven months before the assault while scouting for a base camp on the farm of an anti-Communist confident of the Guatemalan president. His brigade dog tag was numbered 2506.

Leaders of both countries are shown in the documents refusing to take the heat for the Bay of Pigs at a time when the United States pointedly picked them in order to argue “plausible deniability” in the invasion of a sovereign country. Nicaraguan President Luis Somoza wants a promise that, once the exile endeavor is exposed, the U.S. government will protect him from the wrath of the Organization of American States and United Nations for helping Cuban exiles prepare the April 1961 invasion.

But the most dramatic episode is laid out in a 1960 coup attempt in Guatemala. It threatened the U.S. special relationship with Guatemalan President Miguel Ydígoras Fuentes and imperiled Brigade training on a farm belonging to Ydígoras Fuentes’ confidant Roberto Alejo.