With news breaking that President Donald Trump’s personal attorney and fixer, Michael Cohen, is likely to cooperate with federal investigators, one question is what his cooperation might mean for the Russia investigation. Does Cohen have valuable information that could help the Special Counsel learn more or even prove whether Trump campaign associates, or Trump himself, conspired with the Russians in the 2016 election?

Here are some of the most significant areas in which Cohen could likely shed some light.

In a Buzzfeed investigative report — about the work Cohen did on a secret deal to develop a Trump Tower in Moscow with Felix Sater, a Soviet-born American businessman and associate of Trump — there was this jaw-dropping line:

“Even before the appointment of Mueller as special counsel in May 2017, FBI agents investigating Russia’s interference in the election learned that Cohen was in frequent contact with foreign individuals about Trump Moscow — and that some of these individuals had knowledge of or played a role in 2016 election meddling, according to two FBI agents.”

In my written testimony before the Senate Judiciary Committee on Tuesday, I also highlighted that piece of the Buzzfeed report due to its potential significance.

If Cohen was in frequent contact with individuals who had knowledge of or played a role in the 2016 election interference, it would corroborate some aspects of the Steele Dossier. That report, compiled by former British intelligence officer Christopher Steele, suggested that Cohen may have played a central role in the coordination between Russia and the Trump circle. A report from Steele on October 18, 2016, states: “a Kremlin insider with direct access to the leadership confirmed that a key role in the secret TRUMP campaign/Kremlin relationship was being played by the Republican candidate’s personal lawyer Michael COHEN.”

Another Steele report, dated the next day, is titled “RUSSIA/US PRESIDENTIAL ELECTION: THE IMPORTANT ROLE OF TRUMP LAWYER, COHEN IN CAMPAIGN’S SECRET LIAISON WITH THE KREMLIN,” and that report says that Cohen took the lead as the liaison with the Kremlin following the departure of Paul Manafort, Trump’s campaign chairman during the summer of 2016.

The Steele Dossier reported that one of the relevant meetings Cohen had was in Prague, which the Trump team vehemently denied. Cohen tweeted within hours of the Steele Dossier being published by Buzzfeed, “I have never been to Prague in my life.”

I have never been to Prague in my life. #fakenews pic.twitter.com/CMil9Rha3D — Michael Cohen (@MichaelCohen212) January 11, 2017

Within 24 hours of that tweet, the Wall Street Journal reported, “Mr. Cohen told The Wall Street Journal he hadn’t been to Prague since 2001.” Cohen often says contradictory things to news media within a news cycle (see for example Natasha Bertrand’s “Trump’s lawyer has told 4 different stories about the Russia-Ukraine ‘peace plan’ debacle”), but he has adamantly denied at least ever being in Prague during the 2016 elections and since 2001.

In April, McClatchy reported that Mueller’s team has evidence that Cohen “secretly made a late-summer trip to Prague during the 2016 presidential campaign.” No other news outlet confirmed that report, and some commentators reasonably expressed skepticism about the reliability of this particular story. Whether or not a meeting took place in Prague, is less important than whether any such meeting took place — no matter where it was. Other parts of Steele’s reporting seem to hedge on the Prague location, referring instead to a meeting “in an EU country.”

There is one final area to highlight in answer to the question of what Cohen might know about the connection to Russia, and it concerns a so-called Ukraine “peace” deal, the terms of which were favorable to Russia and which Cohen reportedly helped push inside the Trump administration. The Ukrainian politician, Andrii Artemenko, who worked the Ukraine deal with Cohen and Sater told the New York Times that he received encouragement for his plan from top aides to Putin. As I have noted before, the timeline for the Moscow Trump Tower deal , which Cohen and Sater also worked on, may intersect with the work Cohen and Sater were doing to promote the Ukraine plan. The Moscow Trump Tower was financially beneficial to Trump and Cohen, and the Ukraine plan was beneficial to Russia.

A recent report by The Atlantic’s Natasha Bertrand potentially ties Cohen’s Russian connections even more closely into the Ukraine plan. Here’s how:

1. There is some evidence that the Ukraine-Russia “peace” plan received funding from Russian oligarch Viktor Vekselberg.

Curt Weldon, a former congressman — with “connections to both Russia and the Trump campaign” — was reportedly disappointed when news broke of the backchannel deal. “‘We were so close,’ Weldon complained, this source recalled. Then Weldon dropped a bombshell: “He said [he and Artemenko] had already secured funding for the promotion of the plan from Viktor Vekselberg’s fund in New York City,” according to The Atlantic.

In 2014, the FBI publicly warned that a foundation controlled by Vekselberg may have been acting on behalf of Russia’s intelligence services, as NPR’s Tim Mak reported. While some news reports suggest Vekselberg has close ties to Putin, Michael McFaul, a former U.S. ambassador to Russia, told NBC, “I would never describe him as being in the inner circle. He didn’t make his money under Putin. He made his money in the 1990s. But everyone has to make compromises. In fact, he has a complicated relationship with the Kremlin.”

2. Cohen met with Vekselberg and Vekselberg’s cousin Andrew Intrater on Jan. 9, 2017, at Trump Tower where they discussed U.S.-Russian relations under the incoming Trump administration. That’s according to Intrater’s own account of the meeting. Why Cohen, as Trump’s personal lawyer, would be involved in a discussion of incoming Trump administration foreign policy is curious. The three men planned to meet again at the inauguration. Intrater donated $250,000 to Trump’s inaugural committee, and the three men sat together at one of the inaugural dinners.

3. Following Trump’s inauguration, Intrater’s firm, Columbus Nova, awarded Cohen a $1 million consulting contract, and ended up paying him $500,000. Columbus Nova has been directly tied to Vekselberg. As the Washington Post reported, “The website of Vekselberg’s company, Renova Group, listed Columbus Nova as one of its companies in 2017, according to pages that have since been archived. The website was recently pulled down, replaced by a message that it was under construction.”

The backstory of the Ukraine-Russia plan, if the reporting is accurate, looks very much like the foundation for a quid pro quo in dealings with Russia. That said, there could be another explanation that is not tied to campaign interference. If Vekselberg funded the efforts by supplying Cohen with $500,000, for example, that may suggest Cohen’s incentive for advancing the Ukraine plan was financial rather than it being payback for Russian election interference. Or, the explanation could be both.

Mueller will likely now have an opportunity to find out from Cohen himself.