Of course they support the Soviets.
Not only are they and the Soviets pretty much the "whole show" when it comes to "communism" and "allies with the power to back you",but Russia possesses ALL that wilderness in Eastern Russia that is loaded with gold,silver,copper,natural gas,oil,and who knows what else that China desperately needs.
Unlike China,Russia doesn't really need all the money those resources would bring in because they have a MUCH smaller population.
Nobody seems to want to say it,but the China of today is in serious danger of not being able to feed all their domestic slaves,and even domestic slaves can get violent after being hungry and cold for a few days.
China also has a huge military that needs to be fed,clothed,housed,trained,etc,etc,etc.
Chances are there would already be food riots and "revolution in the air" if US manufacturers hadn't bailed China out of bankruptcy by establishing plants there to make their auto parts,industrial tools,etc,etc,etc for cheap using slave labor so the western retailers could maximize their profits.
Not just mechanical fabrication plants,either. I know of at least one Smithfield Foods plant that China bought,closed down,and shipped the whole damn plant back to China,and then hired the foremen that had worked there to move to China to live rent free and get a good salary to show the Chinese how to put it back toether and get it operational. IIRC,the deal was for 3 years,but if they got it up and running in 2,they would get paid for 3,anyway.
And you just KNOW you are not going to see any Chinese wandering around in China,eating hotdogs. ALL that stuff is for sale outside of China so the Chinese can try to pull in enough cash to keep Communism afloat and still feed enough people to keep them from revolting and trying to overthrow the Communist government.