Tariff is a primitive tool, China only retaliate with tariff because that's the language Americans understand, but it's ultimately symbolic as Beijing can just directly order SOEs to stop buying, simliarly import tariffs are also symbolic when China only imports commodities and importers of commodities are basically all SOEs.Can China afford to reduce all existing tariffs by half to all countries except the US? For trades conducted in CNY, reduces the tariff to zero.
If China can afford to do the above, that should be the countermeasure. Money talks at the end and China is a huge market for the world even bigger than the US.
At end of the day if China's goal is eliminate them as a threat, then Trump is already doing everything Beijing could hope for, i.e. forced coupling of smaller nations into China's supply chain, rapid tariff hikes impossible to prepare for and kill off US business, create day to day uncertainty to prevent any company from investing in neither US nor non-China countries, not to mention antagonize the entire world so China can step in to save the day.
And let's not forget China has plenty of coercion power that hasn't been used, at least not publicly, if a country fears the stick, then China also has a bigger one.


