Lol, To much netflix could create fantasy so better minimize watching that since in real life there's no one will notice on bitcoin since if you look on current situation even if there's no war still we can see it unnoticed by many chines and american
Firstly, I have no idea which Netflix movie or show you are referring to here. Secondly, the governments would probably try to gain control of BTC since it is basically money in a digital format and money wins wars.
What good would it do if China hacks Bitcoin? Bitcoin doesn't belong to any country.
Op does have a point here. Even if BTC is decentralized and doesn't belong to any specific country, it is still money which itself is the most important resource when waging wars.
Simple answer... no. As we can see China will rather focus its monetary fund for warfare than spending billions of dollars hacking the Bitcoin Network. It is illogical to hack Bitcoin in the middle of a war.
The Chinese government could actually execute the 51% attack if they possess their own quantum computers secretly hidden away. The same could be mentioned about the USA. BTC could prove to be a valuable resource though the scenario that op described seems impossible.