I don’t disagree with you, but I think the fundamental difference here is that American invasions are a) acknowledged b) considered fairly negatively by virtually everyone, even by those who initially supported them. It is a publically discussed issue with multiple acceptable opinions which range from “expensive quagmire” to “massive human rights violation.”

Tiannamen Square, conversely, was covered up, erased from history and is essentially unknown or uncared about by the majority of the Chinese population.