Lost me there.
Washington had troops in Russia for several years during and after the war, mostly fighting the Reds.
Did Washington miss an opportunity for preventing much of the suffering of the 20th century by aggressively moving against the Reds? Sure.
But it's pure nonsense to claim we supported them.
Correct, and the US supported the White Russians.
The author includes his accusation as the last sentence in a paragraph referring to WWI and 1918, which makes it incorrect.
If he had referred to little more than a decade later, the US did offer aid to the Reds both politically and promotionally.
At best it's sloppy, at worst it's untrue.