They are the least isolationist they have to sell their goods, often by building the roads that carry them.

I think term is protectionist? Not an economist.

We love cheap stuff if the country providing it is weak and not a threat of any kind. Suddenly we don't love good Chinese prices any longer. The massive world wide tariffs are a scheme to restructure the trade order because we have lost control of the WTO, etc to China. We have been so greedy American companies fell over themselves to build factories and joint ventures in China only for China to create competitive companies and force these joint ventures to bankruptcy. Because of the greed, intellectual property and knowledge transfer to China Donald Trump has decided to save the system himself. The stock market being at all time highs doesn't matter if the United States is left empty of capabilities.

Do you think walling their population off from the Internet doesn't qualify?

Economically and diplomatically? No, it doesn't.

Is any foreign Google or Facebook or any social media website allowed to operate in China?

China doesn't allow other tech companies to compete (Google, Facebook, Amazon, etc) .