> You appear to be starting from an assumption that everything USSR did, politically, was left-wing; and thus concluding that fascism can be left wing.
No, I did not. Basically I'm arguing that the USSR pretended to be "left-wing" but were actually "right-wing". So perhaps they were fascist, but that doesn't imply that truly left-wing governments and movements are fascist.
The USSR is what happens when you take left wing to the extreme. Go too far replacing free speech with right speech and you get censorship. Censorship requires a heavy police state to enforce.
You appear to be starting from an assumption that everything USSR did, politically, was left-wing; and thus concluding that fascism can be left wing.
A dictator is diametrical opposed to left-wing ideology.
What you're doing is like saying uxoricide (murdering your wife) is part of FOSS, because a proponent of FOSS did it.