Over the past weeks and months we’ve learned numerous new details about Russian operations in the 2016 election and a long list of contacts between the Trump campaign and Russian nationals or Russian government or intelligence officials. After the revelations of Donald Trump Jr’s meetings in June 2016, we may not yet have evidence of collusion per se. But we have clear evidence of the desire to work directly with the Russian government to defeat Hillary Clinton. With the intent, we know there was no shortage of opportunity. This is the critical, central issue, what did Trump, his family and campaign do with the Russians during their 2016 subversion campaign? But it’s far from the only question. And to make sense of that central question we have to go back further, to the money channel between Trump and the countries of the former Soviet Union which stretches back at least a decade earlier and quite possibly to the 1990s.

Here’s why this is important.

If there’s a there there in the Trump-Russia story, it didn’t come out of nowhere. It almost certainly began in the money channel I described above. The existence of such a channel is neither inherently illegal or subject to any dispute. We know from voluminous reporting that such a channel existed. Money from the countries of the former Soviet Union was key to funding numerous Trump building projects. Russians and nationals from other FSU countries bought up numerous individual apartment units in Trump-branded buildings. A number of Trump’s key business partners and rainmakers were either emigres from the former Soviet Union or Americans who were conduits for money from the same countries. Through these various threads of the story money laundering, organized crime and various kinds of criminal behavior are persistent and ubiquitous. None of this is really up for debate. It’s all been demonstrated by voluminous reporting.

Since I wrote this post a year ago, this has led me to the following cardinal assumption. If there was a quid pro quo between the Trump entourage and Russia during the 2016 election, if there were payoffs, collusive relationships or blackmail those almost certainly grew out of relationships and business dealings that originated in that money channel. Therefore understanding that channel, how it came into existence, what was transacted across it and really everything about it becomes critical to understanding the whole story.

Because of that I early on became very interested in two figures who were clearly part of this money channel and ubiquitous in numerous Trump business projects going back to the first years of the 21st century: Michael Cohen and Felix Sater. Cohen came into Trump’s orbit circa 2006 because he and his family were buying up apartment units in Trump buildings. Cohen is American-born but from early adulthood seemingly his entire professional life was business with emigres from Russia and Ukraine. He was a big player in the Ukrainian/Russian-dominated taxi business, the casino boat business and of course New York City real estate business – all with Russian and Ukrainian emigres. He married a Ukrainian immigrant, as did his brother. He had business interests in Ukraine as well, including an ethanol business he established with his brother and his brother’s in-laws. Somehow, very early on, Cohen became tied into the Russian/Ukrainian emigre community in New York.

Felix Sater grew up in that community. He arrived from Russia at the age of 8 and grew up in the Russian immigrant community of Brighton Beach. In his later professional life, Sater too appeared to be a business conduit for investment funds from the countries of the former Soviet Union. But Sater also had extensive ties to the criminal underworld, both through his father and on his own. Both men, both with deep business and personal ties to the countries of the former Soviet Union, became key business partners of Donald Trump and parts of the Trump Organization. They also show up together at various points of the Trump/Russia story. For instance, they were the two who met with that Ukrainian lawmaker soon after the inauguration to discuss a peace plan for Ukraine and received a packet of paper documents to be delivered to Michael Flynn.

So what is the relationship between these two men? It’s a basic question I’ve been trying to figure out for some time. So this is why I was so fascinated to see Sam Thielman’s story on Sater which notes that the two men actually grew up together. Sater was characteristically loquacious and Cohen stubborn and resistant in their interviews with TPM. But both men confirmed that the relationship dated back decades before either man knew Donald Trump. Sater says he knew Cohen as a guy who was dating a woman from his neighborhood when they were teenagers. Cohen says he just knew Sater from running in the same social circles and that he only started dating the woman he married later.

Just how the two men met is not altogether clear. But there are hints here and there in the public record of overlapping social circles even though they lived in different towns. An early July article in the Times notes that one of Cohen’s uncles, Dr. Morton L. Levine, is the longtime owner of the El Caribe catering hall in Brooklyn. El Caribe hosts weddings and retirement parties. But in the 1980s and 1990s, when Cohen and Sater were teens and young adults, it was also a notorious hangout for members of the Italian and Russian mafia. (As the Times notes, Dr. Levine was never charged with any wrongdoing.) At the height of his reign in 1998 as the head of Gambino crime family, John Gotti held his annual Christmas party there. A year earlier, according to a 2004 New York Sun article, Genovese crime family solider, Ernest “Butch” Montevecchi, hosted a reception at El Caribe for one of his mob subordinates, Tony “Tony L” Luciana, a nephew of Charles “Lucky” Luciano. Just three years later, Montevecchi and Mikhail Sater, Felix’s father, were indicted for running an extortion ring in Brighton Beach between 1990 and 1999.

Sater came into the Trump world in 2001, around the time he began a decade as a cooperating witness and confidential informant for the FBI. Cohen meanwhile entered the Trump organization around 2006 after he came to Trump’s attention for buying up numerous apartment units in Trump branded units. The pre-existing relationship between the two men made us curious whether Sater had brought Cohen into the Trump fold. But both men said that was not the case. Each came into the Trump orbit independently, both told TPM.