Every other intellectual and artist was a communist or socialist back then, but not in any way that seriously threatened the state. They all happily worked on the bomb, after all.
But I can tell when things are being omitted or glossed over.
The fact that those activities led to a thing called McCarthism in the early 1950s is pretty well documented.
Imprisoning Qian for 5 years for a meeting in the late 1930s after his contributions to the war effort was very Red Scare consistent.
To dismiss this whole period as just a "Red Scare" is kind of ridiculous considering how much actual communist infiltration there was.
We won't even talk about FDR's diplomat travelling to the USSR and giving Stalin a kiss in the 30s...