Confucius say: He who interferes in other's fights often wipes a bloody nose.
This fight is Hong Kong socialists vs. China communists. The USA shouldn't get involved. Despite China stealing Karl Marx's intellectual property and not paying any royalties for it, the Chinese version of communism will implode under its own power just like all other communist reigns of terror.
It ain’t imploded, yet. Although I understand Nixon’s reasoning behind it at the time, I think it was an error in the long run to open up China as he did (although Truman bears the greatest responsibility, since he could’ve helped to defeat Mao).