Can't control market, but network.
Partially true, I believe china can directly influence both market the network, china has the largest share and the largest bitcoin user base since mining there is profitable means the miners are located in china at least the ones that mine a lot, and that makes them the ones who influence the price of the bitcoin from time to time.
I guess if all the miners from China would have voted for larger block size, we would have been into larger blocks era by this time, means they are influencing on the network too.