US and Chinese scientists have been collaborating on extremely advanced technologies such as quantum entanglement. QE has the promise of impenetrable communications encryption. This is public information.
Joint research is great when the benefits are mutual. It’s not so great when the research is militarized for offensive purposes.
China is hungry.
China is an ally of the Elite in America. Such sharing is perceived to be beneficial to the elite. Clinton was the first whose sharing activities became public when he transferred missile technology to China so that China could leap to the capability to launch satellites and MIRVed nuclear missiles.