This mean war!

yeah, that's the point, if China stopped allowing manufacturing of phones for the US, the US will be forced to buy elsewhere at a much higher cost

Yes and no. Trade is more complex than the surface. China has other large markets for phones, but losing the US would still hurt them, and there are other countries for companies to do business with to secure manufacturing. China’s economy largely relies on being a global supplier of goods. It’s unlikely companies would abandon the US market over such a thing- so long term they’d likely find and set up another supplier that doesn’t have the antagonistic relationship or at least the power to cause trouble.

All in all the world will keep spinning and even if the price of phones goes up in the US it’s unlikely to do so catastrophically. Large conglomerates can shift profit and cost across their various profit sources or even take slight decreases in profitability to remain cost competitive.

There is just as much change in the long term that China banning export of phones to the US could work out very poorly for them and just fine for us. If Starbucks suddenly refused to sell coffee on the US, companies like Pete’s would make a killing. China has the population for a strong economy but that population can also work against it as well. The biggest economic impact from things like this comes from people’s blind panic influencing market decisions- not from the actual results of a change. What will be will be, but I personally don’t think we should let China push us around. We told them we don’t want Their barns for the same reasons they banned ours. If they want to allow our stuff in maybe it’s worth talking. Otherwise- we can find someone else who won’t take their ball and go home for following the rules they already set up.