China benefit from the competition between Soviet and US, and after Soviet collapsed China not only lost US support but also became US no.1 imaginary enemy
The “reform and opening up” national policy was partially stopped after seeing the disastrous aftermath of Gorbachev’s reforms, after that all reforms would be limited at economic sector. In the 80s there were moderated political reforms as well as freedom of speech in China, but it all stopped with Tiananmen Square Incident.