Explosive memos suggest that a Trump-Russia tit-for-tat was at the heart of the GOP's dramatic shift on Ukraine

An unverified dossier provided to US intelligence officials alleges that President-elect Donald Trump "agreed to sideline" the issue of Russian intervention in Ukraine during his campaign after Russia promised to feed the emails it stole from prominent Democrats' inboxes to WikiLeaks.

The dossier was part of an opposition-research project conducted by a former British spy, Christopher Steele, at the behest of anti-Trump Republicans and, later, Democrats. Steele was the former head of the Russia desk in Moscow for Britain's Secret Intelligence Service, also known as MI6. The memos he wrote made their way to US intelligence officials sometime last year.

A summary of his findings, collected from the network of Russian intelligence sources he had cultivated, was presented to Trump, President Barack Obama, Vice President Joe Biden, and the country's top lawmakers on intelligence matters earlier this month as part of a classified briefing about Russia's intervention in the US presidential election.

The dossier's claim about a Ukraine-WikiLeaks tit-for-tat alleges that Trump would refrain from speaking forcefully, if at all, about Russia's incursion into eastern Ukraine in 2014. In return, Russia would provide WikiLeaks the documents it stole from the Democratic National Committee (DNC).

Throughout the campaign, Trump broke from traditional GOP orthodoxy and established himself as the most sympathetic Republican candidate toward Russia, stressing the need to work with the country on various geopolitical issues.

Trump has not commented on the dossier's specific claims, but he did tweet Saturday, citing a conservative-leaning news outlet, that it was a "complete fraud."

From 'lethal weapons' to 'appropriate assistance'

The Washington Post's Josh Rogin reported last year that "the Trump campaign orchestrated a set of events" just before the start of the Republican National Convention on July 18 to change the language of an amendment to the GOP's draft policy on Ukraine that denounced Russia's "ongoing military aggression" in Ukraine.

The amendment, proposed by GOP delegate Diana Denman at a meeting of the party's national-security subcommittee in Cleveland, called for maintaining and increasing sanctions on Russia in light of its annexation of Crimea and incursion into eastern Ukraine in 2014.

It also proposed "providing lethal defensive weapons" to the Ukrainian military to fend off separatist fighters backed by the Kremlin.

After Denman read her amendment aloud at the meeting, two Trump campaign representatives approached the chairman of the committee and asked that the proposal be tabled, Denman told The Daily Beast at the time.

"When I read my amendment, they got up and walked over and talked to the co-chairmen and they read it," she said. "That's when I was told that it was going to be tabled.

Because campaign representatives are not permitted to publicly debate the merits of an amendment at a subcommittee platform meeting, Denman said the Trump staffers approached her privately and asked her to change the language that called for sending arms to Ukraine.

One of the staffers, J.D. Gordon - then the Trump campaign's national-security policy representative for the RNC - said "Ms. Denman's memory of events is inaccurate."

"I never left my assigned side table, nor spoke publicly at the meeting of delegates during the platform meeting," Gordon, a former Pentagon spokesman, told Business Insider last week.

But the national security subcommittee's co-chair, Steve Yates, told The Daily Beast that he was "reasonably sure that the [Trump] campaign staff were in the room and that they gave an opinion" on Ukraine.

"I just can't say for sure what that opinion was," he said.

'This change came from Trump staffers'

After some debate, the platform passed with a provision to "provide appropriate assistance" to the Ukrainian army rather than provide it with "lethal defense weapons."

It retained much of its tough language on Russia, including its calls to maintain or, if warranted, increase sanctions "until Ukraine's sovereignty and territorial integrity are fully restored."

Gordon, the Trump representative, said that even after the language was altered the platform was "still was much tougher on Russia than the Democrat Party Platform." The Democratic platform refers to Russia's violation of Ukrainian sovereignty but does not call for sanctions on the Kremlin or assistance to Ukraine's army.

Including the call to send arms to Ukraine would not have been extreme or out of step with GOP orthodoxy on the issue, however.

"The language of the original amendment didn't seem strong," said a member of the committee, who requested anonymity to discuss the deliberations.

"It was controversial if you hold Donald Trump's express views on Russia, but not controversial with regard to GOP orthodoxy on the issue," the official said. "So this change on Ukraine definitely came from Trump staffers - not from RNC staffers."

It was particularly surprising, the member added, given the Trump campaign representatives' "relatively hands-off approach" to other parts of the GOP's national-security platform.

That approach seems to have extended to the six other subcommittees tasked with crafting different parts of the GOP platform before the convention. Boyd Matheson, a Utah delegate on the Constitution Subcommittee, told the Daily Beast that the Trump campaign was "nowhere to be seen" during their deliberations.

Gordon, Trump's representative for the national security committee, said that the every sub-committee "featured Trump campaign representatives at side tables to monitor the process and facilitate any questions from delegates."

For his part, former Trump campaign manager Paul Manafort told MSNBC at the time that the change in the GOP's Ukraine policy "absolutely did not come from the Trump campaign."

Paul Manafort, Yanukovych, and WikiLeaks

Prior to the GOP's national security committee meeting last July, Trump had said multiple times that he thought the West should respond more forcefully to Russian aggression.

He gave a speech in Ukraine in September 2015, at the Yalta European Strategy Annual Meeting, where he said that "our president is not strong and he is not doing what he should be doing for the Ukraine." He mentioned that he thought Europe should be "leading some of the charge" against Russia's aggression, too.

But his tone on Ukraine and Crimea appeared to shift after he hired Manafort to manage his campaign in April 2016, as Politico's Michael Crowley has reported.

At the end of July, for instance, Trump told ABC that "the people of Crimea, from what I've heard, would rather be with Russia than where they were. And you have to look at that, also." Days earlier, he had told reporters that he "would be looking at" the possibility of lifting sanctions against Russia for its annexation of Crimea.

Manafort served as a top adviser to a pro-Russian political party in Ukraine between 2004 and 2012, and helped the Russia-friendly strongman Viktor Yanukovych win the Ukrainian presidency in 2010.

Yanukovych was ousted on corruption charges in 2014 and fled to Russia under the protection of the Kremlin.

Secret ledgers uncovered by an anticorruption center in Kiev and obtained by The New York Times revealed that Yanukovych's political party, the pro-Russia Party of Regions, earmarked $12.7 million in undisclosed cash payments to Manafort for his work between 2007 and 2012.

Manafort has denied ever having collected the earmarked payments. But the unverified dossier on which top US leaders have been briefed alleges that Yanukovych "confided directly to Putin that he authorized kickback payments to Manafort," who "had been commercially active in Ukraine right up to the time (in March 2016) when he joined campaign team."

The dossier also alleges that Manafort, who resigned as Trump's campaign manager on August 19, served as a liaison between Trump's campaign team and Russian government officials:

"Speaking in confidence to a compatriot in late July 2016, Source E, an ethnic Russian and close associate of Republican US presidential candidate Donald TRUMP, admitted that there was a well-developed conspiracy of co-operation between them and the Russian leadership. This was managed on the TRUMP side by the Republican candidate's campaign manager, Paul MANAFORT, who was using foreign policy advisor, Carter PAGE, and others as intermediaries. The two sides had a mutual interest in defeating Democratic presidential candidate Hillary CLINTON, whom President PUTIN apparently both hated and feared."

That claim has not been independently verified. The FBI looked into both Page and Manafort last year for their respective ties to Russian officials and business interests.

The same source, "source E," told the author of the dossier that Russia had hacked the DNC and leaked the stolen documents to WikiLeaks "with the full knowledge and support of Trump and senior members of his campaign team."

Trump invoked WikiLeaks dozens of times on the campaign trail, often reading portions of the stolen and leaked emails from the Democratic National Committee and from Hillary Clinton campaign chair John Podesta on the campaign trail.

"I love WikiLeaks,"he told listeners during a campaign rally in Pennsylvania in October. "It's amazing how nothing is secret today when you talk about the Internet."

The dossier states that in return for Russia's feeding the documents to WikiLeaks, "the Trump team had agreed to sideline Russian intervention in Ukraine as a campaign issue and to raise defense commitments in the Baltics and Eastern Europe to deflect attention away from Ukraine, a priority for Putin who needed to cauterise the subject."

Julian Assange, the founder of WikiLeaks, has denied that the Russian government was the source of the hacked documents. As Business Insider's Paul Szoldra has written, however, WikiLeaks'own website seems to disprove his assertion.

"The site's anonymous drop box keeps no record of who submits documents, does not offer or require any identifying information, and there is no single WikiLeaks employee with the power to unmask an anonymous source," Szoldra wrote. "At least, that's what WikiLeaks claims."