"This is a path that it's very hard to turn back on," Fiona Hill warned.
"We've seen many historical episodes where there is violence, people discount it...and the next time around you actually get the real thing," Hill said.
He viewed Russia's president as the "epitome of the badass populist," Fiona Hill said in a Sunday podcast.
Fiona Hill, a former adviser to Trump, said he was so interested in nuclear weapons that he seemed to "surprise" the Russians.
In this extract from Fiona Hill's new book, she reveals how Donald Trump assumed she was a secretary rather than a Russia expert in a crucial call with Putin
Fiona Hill alleged the State Department was instructed to keep tabs on negative comments foreign officials made about Trump.
"In terms of the symbolism of having a sit-down with the American president, absolutely. That is a very important win for Putin," Hill, who served as a top Russia adviser under former President Donald Trump, said.
The former White House Russia adviser said the president avoids insulting leaders like Putin while treating allied leaders "as though they're business counterparts."
Conspiracy theories fixate on a very simple story which acts as a fable for an overarching worldview, explains Philip Seargeant, a senior lecturer in applied linguistics at The Open University.
"It doesn't have to be an either or," Marc Short replied. "it could be both."
Trump promised to surround himself with "only the best people in America." He succeeded, but through no fault of his own.
But Reagan's speechwriter Peggy Noonan concluded also wrote that a "full-blown" trial on impeachment charges "with an election in less than a year, will seem absurd to all but diehards and do the country no good."
James Stavridis, former NATO supreme allied commander, credited Hill for being both tenacious and knowledgeable.
Hill condemned GOP members for propagating the conspiracy theory that Ukraine meddled in the 2016 presidential elections, stressing that Russia was the culprit.
The president is facing impeachment amid accusations that he tried to pressure Ukraine into interfering in the 2020 election to his advantage.
Emerald Robinson of OANN tweeted remarks about Dr. Fiona Hill and Lt. Col. Alexander Vindman, implying that neither witness is American.
#NunesNonsense trended on Twitter Thursday, following remarks from foreign affairs specialist Dr. Fiona Hill on the fifth day of the Trump impeachment inquiry hearings.
Fiona Hill batted down GOP attacks against Vindman: "Everyone immigrated to the US at some point."
"Doesn't it matter that the top U.S. diplomat in Ukraine...said there was a quid pro quo?" Chris Wallace asked.
Senior Conservatives told May that if the advisors didn't go, they would mount a leadership challenge.