China's response will not be ham-fisted but start soft and build until the desired balance is struck. China's response will be intelligent, balanced and diplomatic. Like America's foreign and trade policy used to be.
China will start by encouraging domestic business to buy local or European goods and services. I suspect Chinese airlines will opt more frequently for Airbus than Boeing. Award engineering contracts to Siemens over GE. It will be a gentle, subtle but palatable shift. Industry will try and put pressure on the Gov't and hopefully get the current Administration to reconsider.
If that does not work, China will retaliate by increasing tariffs on key American products. The aforementioned aircraft, and on cars. Guess where General Motors sells 3.9M cars per year? China. (vs. 3.0M GM cars sold in the US). China is a big market and still growing.
https://qz.com/...t-selling-car-there/ China could even start throttling US tech giants from selling there - maybe Apple will be declared 'in cahoots' with the CIA and get banned in China.
At this point trade will decrease and both economies will be feeling the pain. Any victory in such a trade war would be Pyrrhic.
If Trump is (unwisely) willing to keep the trade war going, China may be forced to test its growing geopolitical sphere of influence. It could start convincing, bribing and cajoling the various East Asian nations to pick a side. I suspect many, if not most, will go with China. Why wouldn't they? China is 4 times larger than the US in population, its local, its growing much more rapidly, its been traditional global power for most of its 5000 year history, its culturally more similar.
This is a stupid fight to pick. Its unnecessary. Its quite clear that US History will not look back kindly on Trump, but this trade war decision may be seen as one of the major contributors to accelerating the decline of the American empire.
Remember - It's important to be comfortable in your own skin... because it turns out society frowns on wearing other people's