The Ukraine theory that has consumed Trump's attention has now been taken up by Republicans in Congress who are defending the president against impeachment. Top GOP lawmakers have demanded investigations of Ukrainian interference for which senior U.S. officials, including the director of the FBI, say there is no evidence.
Allegations about Ukraine's role in the 2016 race have been promoted by an array of figures, including right-wing journalists whose work the president avidly consumes, as well as Rudy Giuliani, his personal lawyer. But U.S. intelligence officials told lawmakers and their staff members this past fall that Russian security services played a major role in spreading false claims of Ukrainian complicity, said people familiar with the assessments.
The concern among senior White House officials that Putin helped fuel Trump's theories about Ukraine underscores long-standing fears inside the administration about the Russian president's ability to influence Trump's views.
The White House did not respond to requests for comment.
The Russian Embassy in Washington declined to address whether Putin told Trump that Ukraine interfered in the 2016 campaign, saying only that information about the two leaders' conversations is available on the Kremlin's website.
This article is based on interviews with 15 former administration and government officials, who spoke on the condition of anonymity to offer their candid views about the president.
Aides said they have long been confounded by the president's fixation on Ukraine - a topic he raised when advisers sought to caution him that Russia was likely to try to disrupt future elections.
"He would say: 'This is ridiculous. Everyone knows I won the election. The greatest election in the world. The Russians didn't do anything. The Ukrainians tried to do something,' " one former official said.
Trump, the official said, offered no proof to support his theory of Ukraine's involvement.
"We spent a lot of time . . . trying to refute this one in the first year of the administration," Fiona Hill, a former senior director for Europe and Russia on the National Security Council, told impeachment investigators in October.
The claims that Ukraine sought to tilt the 2016 election have taken several forms. One early version was promoted by Paul Manafort, Trump's then-campaign chairman, who suggested to campaign aides as early as the summer of 2016 that Ukrainians may have been behind a hack of the Democratic National Committee (DNC), rather than the Russians, his deputy, Rick Gates, later told federal investigators.
Gates said that Manafort's theory "parroted a narrative" that was advanced at the time by Konstantin Kilimnik, an employee of Manafort whom the FBI has assessed to have connections to Russian intelligence. (Kilimnik, who is believed to be in Moscow, has denied such ties.)
Two weeks after Trump took office, Putin floated another claim: that figures in Ukraine had helped boost Democratic nominee Hillary Clinton.
"As we know, during the election campaign in the U.S., the current Ukrainian authorities took a unilateral position in support of one of the candidates," Putin said at a news conference in Budapest on Feb. 2, 2017. "Moreover, some oligarchs, probably with the approval of the political leadership, financed this candidate."
Ukrainian steel magnate Viktor Pinchuk's foundation donated millions of dollars to the Clinton Foundation, but there is no evidence that he contributed money to Hillary Clinton's campaign, which would be prohibited under federal law. Pinchuk has also supported Trump: In 2015, he made a $150,000 donation to Trump's foundation.
RT, the Russian government-funded media network, spotlighted other arguments that Ukraine worked to help Clinton's campaign, focusing on contacts between a part-time DNC consultant and Ukrainian Embassy officials in Washington.
"Democrat-Ukraine collusion seems far deeper than anything so far proven between the Trump campaign and Russia," an op-ed columnist wrote in July 2017.
Trump added his own twist on the conspiracy theory in April 2017, in his first public allegation about Ukraine's role.
In an interview with the Associated Press, the president claimed that CrowdStrike, a computer security company the DNC hired to investigate the breach of its email systems, was based in Ukraine and played some role in hiding evidence from the FBI.
"Why wouldn't [Clinton campaign chairman John] Podesta and Hillary Clinton allow the FBI to see the server? They brought in another company that I hear is Ukrainian-based," Trump said. "I heard it's owned by a very rich Ukrainian, that's what I heard. But they brought in another company to investigate the server. Why didn't they allow the FBI in to investigate the server?"
In fact, CrowdStrike is based in California, and it is not owned by a Ukrainian. Dmitri Alperovitch, the company's co-founder, is a Russia-born U.S. citizen who is an expert in cybersecurity and national security.
It is unclear where Trump first got the idea of a Ukrainian connection to CrowdStrike. At the time, the notion was not yet being widely discussed on Twitter, his social media platform of choice and a fertile bed for disinformation, according to social media experts.
"Prior to Trump's mentioning it in his interview with the Associated Press, the idea that CrowdStrike was Ukrainian based and concocted the story of the DNC hack existed on social media, but was far from mainstream," said Darren Linvill, an associate professor of communication at Clemson University who studies social media and online disinformation and conducted an analysis of tweets during that period for The Washington Post.
"On Twitter, messages pushing the argument can be measured in the hundreds, not even the thousands, and in this context those are small numbers," Linvill said.
Trump has returned to the false Ukraine-CrowdStrike connection many times, arguing that the company had covered up Ukraine's hacking of the DNC and that it had even spirited the DNC server to Ukraine, former White House officials said.
In June, for instance, he called in to Sean Hannity's Fox News program and repeated his complaint that the FBI hadn't taken possession of the DNC email server.
"How come the FBI didn't take the server from the DNC? Just think about that one, Sean," Trump said.
That same day, Breitbart News had published a story about the FBI relying on information from CrowdStrike.
In fact, the bureau's forensic experts had taken complete copies of dozens of servers used by the DNC, which then-FBI Director James Comey later testified was an "appropriate substitute" for examining the actual equipment. The intelligence community also knew months before CrowdStrike was hired that the Russians had infiltrated the DNC.
Most significantly, Trump raised CrowdStrike in the July 25 phone call with Ukrainian President Volodymyr Zelensky that led to his impeachment.
"I would like you to find out what happened with this whole situation with Ukraine, they say Crowdstrike . . . I guess you have one of your wealthy people. . . . The server, they say Ukraine has it," Trump said, according to a memorandum the White House released of the call.
Privately, officials tried in vain to convince the president that CrowdStrike was not a Ukrainian company and that it would be impossible for the server to be located there, a former administration official said.
One of the officials who Hill said tried to convince Trump, former homeland security adviser Thomas Bossert, publicly pleaded with the White House in September to drop the Ukraine theory, which he called "completely debunked."
"The DNC server and that conspiracy theory has got to go," he told ABC News's "This Week." "If he continues to focus on that white whale, it's going to bring him down."
Bossert pointed to Giuliani, Trump's personal lawyer, as a persistent source of the server claim. "I am deeply frustrated with what [Giuliani] and the legal team is doing in repeating that debunked theory to the president. It sticks in his mind when he hears it over and over again."
Trump's suspicions about Ukraine manifested in other ways. Early in the administration, then-Ukrainian President Petro Poroshenko was eager to secure a White House meeting with Trump - ideally before he met publicly with Putin - to demonstrate U.S. commitment to defending Ukraine against Russia.
But Trump resisted the meeting, according to former U.S. officials with direct knowledge of the matter. White House aides were confused: Ukraine was an ally in a war against a country that had just undermined the U.S. elections. Meeting with Poroshenko was a "no-brainer," one former official said. "It was utterly mystifying to us why Trump wouldn't agree."
Another former official said it was clear from the beginning of Trump's presidency that he wanted to improve relations with Russia and form a bond with Putin.
John Kelly, who served as Trump's chief of staff from mid-2017 until the end of 2018, marveled to other aides that Trump expressed far less skepticism of Putin, whom Trump sometimes called "my friend," than other leaders, said a former senior White House official.
Kelly tried to get U.S. experts to speak to Trump before his scheduled calls with the Russian president to push back on some of Trump's misconceptions, the official said.
Some wondered whether Trump's coolness toward Ukraine was intended not to offend Putin.
Poroshenko came to the White House on June 20, 2017, to meet with Vice President Mike Pence. Trump had a short "drop-in" with the Ukrainian leader, allaying some U.S. officials' concerns that he wouldn't bother to say hello.
The two leaders posed for photos with reporters in the Oval Office and made short remarks. (Notably, Trump did not mention Ukraine's war with Russia.) But the brevity of their encounter underscored Trump's reticence. He had already met with several foreign leaders, for more formal, longer meetings, followed by joint news conferences. Trump hadn't snubbed Poroshenko, but he hadn't strongly embraced him, either.
The meeting stood in stark contrast to Trump's warm reception a month earlier of Russian Foreign Minister Sergei Lavrov and Sergey Kisylak, who was then Russia's ambassador to the United States. Trump told his guests that he was unconcerned about Moscow's interference in the 2016 U.S. presidential campaign because the United States did the same in other countries, an assertion that prompted White House officials to limit access to the remarks to an unusually small number of people, according to three former officials with knowledge of the matter.
U.S. officials who had been working to deter Russia were aghast. They thought the Russians would take it as a signal that they were free to interfere in upcoming U.S. elections and those in Europe, as well.
On July 7, 2017, Trump had his first in-person encounter with Putin, at the G-20 meeting in Hamburg. Their highly anticipated formal conversation lasted more than two hours. But later that day, they met informally for an additional hour, at a dinner for heads of state and their spouses.
At the time, U.S. and Russian officials didn't disclose the conversation. During the meal, Trump left his chair and sat next to Putin. Trump went alone, and Putin was assisted by his interpreter.
For some White House officials struggling to understand Trump's obsession with Ukraine, the Hamburg meetings were a turning point.
Three former senior administration officials said Trump repeatedly insisted after the G-20 summit that he believed Putin's assurances that Russia had not interfered in the 2016 campaign. The officials said Kelly, national security adviser H.R. McMaster and Secretary of State Rex Tillerson all tried to caution Trump not to rely on Putin's word, and to focus on evidence to the contrary that U.S. intelligence agencies had collected.
Over the next several months, Trump privately told aides on several occasions that he believed Ukraine had interfered and tried to help Clinton win the White House, former officials said.
"The strong belief in the White House was that Putin told him," one former official said.
Trump repeatedly told one senior official that the Russian president said Ukraine sought to undermine him, the official said.
There was no evidence that Putin pushed the Ukraine theory with Trump in their official phone calls and meetings, which were witnessed by interpreters and aides, several former administration officials said.
However, White House aides were not part of Trump's private conversation with Putin in Hamburg, or a later meeting he had in Helsinki for two hours with the Russian president, when they were accompanied by only their interpreters.
Trump also took steps to conceal the details of his formal meeting with Putin in Hamburg, taking the notes away from his interpreter and instructing her not to discuss what had transpired with other administration officials, The Post reported earlier this year.
In the wake of Hamburg, top leaders were dispatched to try to convince him that Russia interfered in the campaign. On different occasions, Kelly asked Bossert, CIA Director Mike Pompeo, Director of National Intelligence Daniel Coats and his principal deputy, Sue Gordon, to brief the president on the intelligence community's Russia assessment, said former officials with knowledge of the briefings.
They did not convince him.
A year after Trump met Putin in Hamburg, they reconvened at a summit in Helsinki. After his one-on-one with the Russian president, Trump expressed doubt that the Kremlin interfered in the campaign.
"My people came to me, Daniel Coats came to me and some others, they said they think it's Russia," Trump said at a joint news conference, standing beside the Russian leader. "I have President Putin; he just said it's not Russia. I will say this: I don't see any reason why it would be, but I really do want to see the server."
Intelligence officials were stunned that Trump would publicly side with Putin over his own advisers. His comments also revealed that he still clung to his suspicions about Ukraine.
"I really believe that this will probably go on for a while, but I don't think it can go on without finding out what happened to the server," Trump said.
Later that day, Coats issued a public statement that read like a rebuke.
"The role of the Intelligence Community is to provide the best information and fact-based assessments possible for the President and policymakers," Coats said. "We have been clear in our assessments of Russian meddling in the 2016 election and their ongoing, pervasive efforts to undermine our democracy, and we will continue to provide unvarnished and objective intelligence in support of our national security."
But after returning to Washington, Trump continued to press the Ukraine theory with more frequency, former officials said. They worried that his meeting with Putin had again influenced his thinking.
In the run-up to Trump's impeachment, some GOP lawmakers have echoed the Ukraine-did-it theory, weaving together events that did occur - such as the then-Ukrainian ambassador's criticism of Trump in a 2016 op-ed - as part of a conspiracy they equate with the Kremlin's intelligence operation.
"The Democrats cooperated in Ukrainian election meddling," Rep. Devin Nunes of California, the ranking Republican on the House Intelligence Committee, alleged at a Nov. 14 hearing to collect evidence for the impeachment.
Sen. John Neely Kennedy of Louisiana, suggested in a Fox News news appearance that Ukraine, not Russia, may have broken into the DNC's email system. He later retracted the comment, but in a subsequent interview on "Meet the Press," Kennedy said "both Russia and Ukraine" had interfered in 2016.
Sen. Ted Cruz of Texas, told the same program this month that there was "considerable evidence" that Ukraine had interfered.
This fall, U.S. intelligence officials informed lawmakers about what they have concluded has been an organized campaign by Russian propagandists to spread the Ukraine theory on social media, said people with knowledge of the reporting.
The reports by intelligence analysts cite evidence that the propagandists were taking credit for helping to spread disinformation that equated Ukraine's actions to Russia's, and celebrating the traction it was getting, particularly with conservative news organizations.
The intelligence reports were shared with members of Congress and their staff, including lawmakers who have in recent weeks become some of the most vocal advocates for investigating Ukraine's alleged interference, said people with knowledge of the matter. The New York Times first reported the briefings to lawmakers.
In her public testimony in the impeachment proceedings, Hill, the NSC's former Russia director, admonished lawmakers not to take the Kremlin's bait.
"Based on questions and statements I have heard, some of you on this committee appear to believe that Russia and its security services did not conduct a campaign against our country - and that perhaps, somehow, for some reason, Ukraine did," she said. "This is a fictional narrative that has been perpetrated and propagated by the Russian security services themselves."
Hill implored the lawmakers not to help Russia's campaign. "In the course of this investigation, I would ask that you please not promote politically driven falsehoods that so clearly advance Russian interests."
Last month, RT rejected the idea that Russia had promoted such a narrative, noting that Putin said in July that he did not think the actions of wealthy individuals in that country amounted to "interference by Ukraine."
More recently, however, the Russian president has expressed satisfaction in the new focus on Ukraine.
"Thank God no one is accusing us of interfering in the U.S. elections anymore; now they're accusing Ukraine," the Russian president said at a news conference in Moscow in November. "Well, let them sort this out among themselves."