I think the UK/EU and many others are just being pragmatic. They know a trade war benefits no one, so are holding back and trying to minimise the damage. What they do in public and say and plan in private are likely to be very different.
The real damage is the destruction of decades of trust that will take at least until 2029 to be restored. With this level of uncertainty planning is impossible so new trading arrangements are likely to emerge, in which the USA is not involved.
How China handle this is more difficult to predict. They won’t though be bullied and have much greater capacity to weather a storm than the USA. They can deal with protests swiftly. I am much more impressed with China’s quiet diplomatic dignity than I am with Trump’s bluster and suspect that so too is the rest of the world. Which isn’t a good look for the USA or the western countries.
Are you suffering buyers regret yet?