the thing i find craziest about the tiananmen square propaganda is that there is a PBS Frontline documentary that is sponsored by the Ford Foundation that interviews people involved in Tiananmen square who say there was no massacre. These people are organizers of the student protests. This documentary (I believe it's called The Gate of Heavenly Peace) was produced in the early 90s and it could be where some of these clips come from (at least that screenshot of the interview looks familiar). I think there is even one interview with one of the organizers who admits their intention was to spark violence.
Anyway I don't really know what the American attitude toward Tiananmen Square at the time was but I saw this documentary a few years ago and was kind of surprised by how against the narrative it is.