Isn’t the worst socialism still better than the best capitalism? Why try to destroy “revisionist” socialism when you have capitalism to destroy? Wouldn’t it be easier to fix a revisionist socialist country than trying to convince a capitalist one to be socialist?
For the USA it would of been logistically absurd for them to try invading China, they failed to even subdue Vietnam which could of served as a foothold if they did. Likewise, China at the time simply didn't have the naval assets to challenge the USA's established positions in the Pacific.