"An eye for an eye makes the whole world blind."

And competitive brinksmanship, xenophobia, and walled isolation aren't useful unless you're running DPRK.

I'm sure it's fueled by xenophobia, but if we think of China / US as competing technology firms, the decision makes even more sense. What tech firm would want a one-sided relationship where their employees share information using a competitors platform, when you have no guarantee of privacy?

I don't think the walled isolation claim sticks - the US would not be seeking to isolate itself. Instead, it would be requiring both countries to operate on the same playing field. Why would anyone want to play a game when the other side won't agree to the same rules?

Seems to be a good strategy for some situations like the iterated prisoner's dilemma.

https://en.wikipedia.org/wiki/Tit_for_tat