CARACAS, Venezuela >> Around May 2017, an unusual request from a prominent Venezuelan general made its way to the White House: Gen. Ivan Hernández, head of both the presidential guard and military counterintelligence, wanted to send his 3-year-old son to Boston for brain surgery and needed visas for his family.

After days of internal debate, the still young Trump administration rejected the request, seeing no point in helping a senior member of a socialist government that it viewed as corrupt and thuggish but wasn’t yet prepared to confront.

That decision, revealed to The Associated Press by a former U.S. official and another person familiar with the internal discussions, might have gone unnoticed if National Security Adviser John Bolton hadn’t admonished Hernandez this week on live TV as one of three regime insiders who backed out of a plan — allegedly at the last minute — to topple President Nicolás Maduro.

It might also have been one of several missed opportunities to curry favor with Venezuela’s normally impenetrable armed forces.

The U.S. also rebuffed a back channel to the alleged ringleader of the would-be defectors, Defense Minister Vladimir Padrino Lopez.

Bolton said Hernández, Padrino and Supreme Court Chief Justice Maikel Moreno chose to stick with Maduro at the moment of truth: when opposition leader Juan Guaidó appeared Tuesday on a highway overpass surrounded by a small cadre of armed troops ready for what he said was the “final phase” of a campaign to rescue Venezuela’s democracy known as Operation Freedom.

Little is known about the extent of support for the plot. Opposition leader Leopoldo Lopez said Thursday he had been speaking for weeks with military commanders while under house arrest. U.S. special envoy Elliott Abrams said there was even a document with the outlines of a transitional government that top officials had agreed to.

“I am told the document is long —15 points, I think — and it talks of guarantees for the military, for a dignified exit for Maduro, and Guaidó as interim president,” he told Venezuelan online TV network VPItv.

The three officials haven’t directly denied they were in talks with the opposition, but they have reaffirmed their loyalty to Maduro and remain in their posts. A fourth, Gen. Manuel Figuera, head of the feared SEBIN intelligence agency, did break ranks and has since disappeared.

But some analysts doubt top military officials who have amassed immense power under Maduro, and are sanctioned by the U.S., ever seriously considered betraying him. Instead, they speculate that the opposition — and by extension, the U.S. — may have been duped by Cuban intelligence agents in Venezuela.

“They try to buy us as if we were mercenaries,” Padrino said Thursday in remarks alongside Maduro.

One clue to the military officers’ apparent reluctance to join any U.S.-backed plot may be found in the story of their past, failed dealings with senior American officials.

The former U.S. official and two other people agreed to discuss details of the previously undisclosed interactions on the condition they not be identified because of the sensitive nature of what were private, high-level talks inside the Trump and Obama administrations.

For years, U.S. officials tried to identify ways to engage the military, the traditional arbiter of political disputes in Venezuela. But after Hugo Chavez’s thorough scrubbing of U.S. influence in the armed forces, opportunities were limited.

That’s why, with the benefit of hindsight, Hernandez’s visa request stood out.

A letter addressed to the U.S. Embassy in Venezuela from Boston Children’s Hospital states that Hernandez’s son had been authorized for surgery on March 14, 2017, for which the family had made a $150,000 deposit. It states that it is “in the child’s best interests” if both Hernandez and his wife were granted visas to accompany the child during what was expected to be a two-month convalescence. The letter was provided to the AP by one of the people familiar with the matter.

After the request for humanitarian visas was rejected, a former senior Venezuelan official cooperating with U.S. law enforcement appealed to his contacts in Washington on Hernandez’s behalf. However, once again the request fell on deaf ears, reflecting what one of the sources viewed as a lack of strategic thinking by top policymakers in the White House and State Department.

“There’s legitimate skepticism on the part of the U.S. to engage given the amount of Cuban coaching of the Maduro government,” said Douglas Farah, a national security expert on Latin America and president of IBI Consultants.

“But clearly a humanitarian request can break through a lot of ideological barriers and pay major dividends down the road,” added Farah, who had no direct knowledge of the episode.

There was no immediate comment from the White House.

But the former U.S. official disputes the view the visa request was never seriously considered. While he said there was some sympathy for Hernandez, he noted that for years top civilian and military loyalists have enjoyed unfettered access to the U.S. — where billions stolen from Venezuela’s state coffers are invested — and nonetheless showed no interest in working with the American government to restore the rule of law in the oil-rich nation.

Further, for almost two decades of socialist rule and until summer 2017, when the Trump administration toughened its stance in response to Maduro’s crackdown on protests, regime change hadn’t been the U.S. policy goal. So White House officials didn’t want to be seen as encouraging a barracks revolt and were wary of interacting with officials facing U.S. investigations for drug trafficking or corruption.

“If any senior official is going to join a plot, it’s because of a cool assessment of its chances of success, not because their son got medical treatment in the U.S. two years ago,” the former U.S. official said.

A year before Hernandez was rebuffed, his boss, Defense Minister Padrino Lopez, also sought contact with the U.S., according to the two other sources familiar with the matter.

In early 2016, a trusted associate, retired Gen. Jimmy Guzman, traveled to Washington for a meeting with a senior official from the U.S. Defense Intelligence Agency. Over lunch at a Georgetown hotel, Guzman expressed Padrino’s interest in opening a channel of communications with the U.S. and Maduro’s opponents after the opposition’s upset victory in December 2015 congressional elections.

But after Guzman returned to Caracas, the Americans abruptly cut off communications, according to the two people, when socialist party boss Diosdado Cabello identified the two Venezuelan exiles who brokered the meeting, accusing them on TV of working with the U.S. to carry out a coup.

One of the sources said the U.S. feared Padrino had been feigning interest in order to collect information for Maduro about what the Americans were up to.

Padrino had long been viewed as a potential white knight. He’s one of the last active-duty officers who studied in the U.S., having been trained in psychological operations at the School of the Americas — a familiar Chavez boogeyman for its role in training generations of right-wing military dictators — and then at the Army Infantry School, both located at Fort Benning, Georgia.

Former classmates remember him as an exemplary student who enjoyed his two years in the U.S. in the 1990s, renting a town house off base and starting a family. His two children have U.S. passports, one source said.

He surprised many in the U.S. and opposition by taking a conciliatory stance in the tense hours following the 2015 elections in which speculation swirled that Maduro wouldn’t recognize the opposition’s win. Surrounded by the entire military command, he urged calm in a televised address and celebrated the still-unannounced results as a victory for Venezuela’s democracy.

More recently, the U.S. has hardened its position toward both men. After the Trump administration at the start painstakingly avoided targeting the military, in the hopes of giving it space to pressure Maduro, it slapped financial sanctions on Padrino in September. A few months later, it was Hernandez’s turn. The U.S. Treasury accused him of commanding a state intelligence operation blamed for “brutal beatings, asphyxiation, cutting soles of feet with razor blades, electric shocks, and death threats.”