Imagine conflict breaking out and China disrupting most of the US's consumer network infrastructure. (read: everyone's DSL/cable modem and some amount of data center equipment.) The chaos and mayhem would be enormous.

Feasible. But let's not pretend it would stop nuclear ICBMs from launching.

Which is, paradoxically, why massive numbers of traceable nuclear weapons + early warning actually make the world a safer place. (At least for major-power, global conflicts)

I could easily be wrong, but it's hard for me to imagine that waging war is the Chinese objective here. Wars are costly, and destructive, and unpredictable.

But tech espionage would fit nicely into a different, long-term game. There is (of course) a lot of work left to do spread the modern economy to the rest of their country. But if they can do that, they will have a huge population advantage and be the largest market in the world. Meanwhile they are already competitive (if not dominant) in manufacturing. So what's left? Tech.

If they can become competitive with (or even leap-frog) the West technologically, they'll really be the de-facto leader of the world in every economic dimension.