I don't think China will be able to take over the bitcoin network, because we know the Chinese government really hates bitcoin, but I admit that China dominates in bitcoin mining, but if the problem is they want to take over the bitcoin network, I don't think it will be possible, even though they do. any way, I'm sure they will not be able to do it all..
China is an old fox in scams and changes between black and white very quickly, a stormy day will allow them to confide in their interest in bitcoin, even disgust for the network but as long as the situation of the world and surrounding countries show special behavior with bitcoin, they become a more friendly and sociable face. The takeover is probably also one of the few strategies they are working on, even readying parts to manage, it's just that they're not the only wolves in this world, countries all have an insularity about the bitcoin network as well as approaching takeovers.
Nobody knows whether they have taken it over already or not. From my point of view the easiest takeover could already have happened years ago when Bitcoin was so cheap that a country like China would laugh about the money they needed to purchase a couple of million Bitcoins. Why is it a takeover and the most effective one probably? If the world gets into problems with a hostile China and it is discovered that China owns 25% of the units of the most powerful value network in the world, that would be the end for it I think. Then again China would probably keep it a secret and reign over the world with richness.