He has been mocked by President Trump as a "low level volunteer" and "proven to be a liar."
"I believe history will remember him like John Dean," said Italian-born Simona Mangiante, referring to the former White House counsel who pleaded guilty to his role in the Watergate coverup and then became a key witness against other aides to President Richard Nixon.
Dean told Nixon in 1973 that Watergate was a "cancer on the presidency," warning him that it was an existential crisis that could imperil his term in office.
"George is very loyal. And he is on the right side of history," added Mangiante, who got engaged to Papadopoulos in September.
Mangiante said she was advised by Papadopoulos's lawyers not to answer specific questions about his activities during the 2016 presidential campaign or what he has told the FBI.
But she indicated in an interview that she believes he ultimately will emerge as more than a bit player in the Russia probe — and that his decision to cooperate after he was arrested getting off an airplane at Dulles International Airport in July was a key turning point.
Without offering specifics, Mangiante said there is much more that has not yet been told publicly about Papadopoulos' 10 months as an informal national security adviser to Trump and his interactions with a London-based professor who told Papadopoulos, according to court filings, that the Russians had "dirt" on Democratic candidate Hillary Clinton.
"There's a lot to come," she said. "He was the first one to break a hole on all of this."
She said Papadopoulos was not a "coffee boy," as he was once tagged by former Trump adviser Michael Caputo, a nickname she found especially galling. "I know what it means as a young person to do all the efforts you do to build your career and be dismissed as a coffee boy," she said.
Despite restraints placed on her by the terms of Papadopoulos' ongoing cooperation agreement with the special counsel, Mangiante said she has been speaking to reporters to defend his reputation and try to explain how the lives of her and the Chicago-born former energy consultant have been upended by the events of the last year.
Mangiante said she has been extensively interviewed by Mueller's team, who asked about her own brief stint working for Joseph Mifsud, the same London professor who offered to connect the young Trump aide with the Russians.
Mangiante, who was born near Naples and trained in law and international relations, said she met Mifsud while working with the European Parliament in Brussels.
Mifsud, a former Maltese government official who had an affiliation with an Italian university, was friendly with the head of the parliament's socialist party and was often at receptions or events, she recalled. Eventually, Mifsud offered her a job at one of his London organizations.
Mangiante accepted in July 2016 but said she only worked for the group for three months, quickly concluding that it was "a facade for something else."
She said she never heard Mifsud discuss Russians but quit when she was asked by his partner to attend a secret meeting to discuss Iraq in Tripoli. "I thought it was very suspicious," she said.
Mangiante said she heard about Papadopoulos, who at the time was serving as a Trump adviser, during her brief time at Mifsud's group. But she said did not meet him until the spring of 2017, after his involvement with Trump had ended. He sent her a message through LinkedIn, noting that they had both had connections to Mifsud's group.
Soon, the two were communicating online and, after meeting in London, quickly fell into a romance, she said. They spent the spring and summer traveling together in Europe. Though Papadopoulos had been interviewed by the FBI in January and again in February, she said he did not seem concerned at the time about what could be coming.
Until his July arrest.
"We went from paradise to hell," she said.
She said she was in Chicago with his family at the time and the following weeks were stressful and scary. His decision to make a deal with prosecutors and plead guilty to one felony while cooperating with the FBI, she said, was ultimately not a tough one.
"It was brave," she said. "It wasn't hard, but it was brave . . . It's always easiest to say the truth about everything."
Mangiante said she is now spending much of her time in the United States because Papadopoulos is barred from traveling by the terms of his agreement. The date of his sentencing has not been set yet.
"This has changed his life forever," she said.