China is still trading with other countries. While it may take a hit from US companies pulling some manufacturing out of China, some of those will be replaced by other - both Chinese and foreign - companies. Especially other foreign companies operating in China will profit from reduced competition for Chinese labor / manufacturing, encouraging them to move more manufacturing there. This will blunt the impact of manufacturing for the US market disappearing.
Also US companies will only withdraw in part from from China, since they can still manufacture goods intended for anywhere else in the world there - just not for the US.
In the end China will take a hit, but nothing close to requiring those measures you're picturing.
The US will have to bootstrap a lot of manufacturing to replace Chinese labor. This will sound good on paper and look good on some economic metrics, because it requires domestic investment. But since the American lifestyle won't be "subsidized" by cheap and exploitative Chinese labor anymore, the average American may actually find himself to have less than before.
And the rest of the world will profit from having two major players intentionally cripple each other.