One seven-letter word ― “synergy” ― may prove critical in proving the allegations that President Donald Trump colluded with Russia, according to Washington Post columnist Jennifer Rubin.

Rubin asked in her column Monday what would happen if “collusion” wasn’t just defined (as it has been by many) as the alleged “plot operating in 2016 between then-candidate Donald Trump and Russians to manipulate the election” but was actually widened to include an earlier alleged 2015 “plot” for Trump to “make hundreds of millions” on projects while denying “any deals” with the Russians.

“Notice the word ‘synergy’” in special counsel Robert Mueller’s sentencing memorandum in the case of Trump’s former personal lawyer Michael Cohen, Rubin wrote. She added:

“According to Mueller, Michael Cohen was contacted shortly after Trump declared his candidacy, in November 2015, by a ‘trusted person’ in the Russian government who could offer the campaign ‘political synergy’ and ‘synergy on a government level.’”

Rubin claimed that “all of Trump’s collusion denials crumble” if there was “concrete evidence of Trump’s approval (how could there not be?) to cooperate with Russia to make money and get some help.”

“Tying Trump to collusion in 2015 makes it interesting but non-essential to prove, for example, that he knew the Trump Tower meeting was ongoing,” she added. “Knowledge of the overall scheme with a foreign power would be more than enough to incriminate Trump.”

“In sum, if synergy is collusion and Trump was in on it, we have collusion,” she wrote, later adding: “If the collusion extended to coordination and assistance from a foreign government, would almost certainly be illegal.”

Read Rubin’s full column here.