Yeah all the photos and film of Tiananmen Square are surely just propaganda right? That event was just made up by the US and definitely wasn't witnessed by and broadcasted by several different countries' news services.
The US has done some bad shit, and still does. But do not let that blind you to the crimes of other countries. There's a reason why the Chinese government censors mentions of June 1989 and the mass deaths due to famine during the great leap forward.