Only in economic terms. Sure, China would face a massive shortfall and would have huge unemployment if it suddenly stopped exporting to the USA. But that's not the same world of trouble as suddenly being unable to get important technology and parts, which is what the US would face. And China is really not reliant on imports from the USA - especially not in time of war (that is, they might have a problem selling things legally without paying various royalties to US companies - but that doesn't matter anymore in a world War).
I don't see what the mutual dependency is. They sent us cheap shit for a few decades, we gave them dollars in return. Our inflation rate was super low, as we were exporting our inflation. We slowly lost the ability to make stuff domestically. That system is now crumbling, China is using their exports to buy gold instead. We are left with a hollowed out economy based on services and finance. The DOD is having a big problem building ships and submarines. Nuclear power plants can't be built affordably. In some ways, China is in the same position as the USA was during WW2, the world's factory.
I think that was the idea, but in practice I think that China successfully outmaneuvered the United States by taking advantage of the short-sighted greed of our businesses leaders.
They are now the manufacturing capital of the world, and our position of being the preeminent consumer in the world lasts only as long as our consumers can afford to purchase things.
These are long lived relationships -- they may have outmaneueverd at some points, and also restrained at others.
China runs a precarious political situation which is only as strong as the country is economically stable - which currently it is veering to unstable.
It goes without saying the US is also in a precarious situation - it is much more publicized due to the nature of the US airing all its dirty laundry publicly.
