One thing about Stalin’s crimes I learned about from the “right-wing” radio show (”Voice of Americanism”-Dr. William Steuart McBirnie) in the 1970’s was “Operation Keelhaul” when millions of Russians were forced back to the USSR by the US-UK and their fate in the Gulag (they had seen the West and or fought for Hitler).
Solzhenitsyn noted it in “Gulag Archipelago” putting blame on FDR and Churchill.
A book was written about it here in the USA called “Operation Keelhaul” and I read an account of this disgusting thing in of all places the autobiography of William Sloane Coffin, anti-Vietnam War cleric.
Coffin was involved in it during his military service.
F.D.R referred to Stalin as "Uncle Joe" and plenty of libs in our government were and are Soviet sympathizers - or Soviet copycats, like the current Deep State is now despite claiming to be anti-Russia.
Putin, Zakharova, and Russia succeed today in hiding behind the "WWII Victory" banner, instead of being forced to acknowledge that Stalin turned out to be worse than Hitler. This is largely because of the U.S. govt's own legacy of whitewashing Soviet crimes as we allied with them militarily for a time.
See film: Mission to Moscow. At F.D.R.'s request: Stalin's purges and terrors were essentially justified in the name of defeating the Nazis.
https://en.m.wikipedia.org/wiki/Mission_to_Moscow