Russia is actively threatening nuclear war. That’s a threat to everyone, not just Europe.
With the caveat that China will export all that extra inflation to them which will exacerbate the domestic problems Biden faces.
If however China was to invade Taiwan and US/EU were forced to impose sanctions on them then you can basically expect a financial nuclear winter, everyone will be in pain, US most of all. China actually is a highly self-sufficient economy outside of energy markets (which it could adapt to especially if Russia remains an ally) while the US is heavily import dependent from China (hence the whole trade imbalance/surplus that Trump was bitching about).
TLDR: No one currently cares about Russia sanctions except Europe. The world can't afford Chinese sanctions.
China depends a lot on importing food, especially meat. The two most essential things they need. Food and Energy. And they currently struggle with both.
They have already declined to impose sanctions on Russia because of their reliance on Russia for raw materials and fertilizer.
Lets just hope none of this ever happens. I live in Taiwan at the moment. I just want to enjoy life with my family.
History is full of nuke threats and no follow through (well except 2 incidents).
But I moved on from moderate uncertainty leading to a default of skepticism.
Some actions have very predictable outcomes even if they aren't guaranteed. with those I like to use the vernacular that implies certainty. That's how I feel about nuclear exchange. But I don't associate the probabilities of expectation of nuclear exchange and invasion as conditional upon each other. A surprise outcome in an invasion of a nonnuclear non-nato state wouldn't lead me to feel a nuclear exchange probability suddenly becomes inverted similarly.
Because countries have invaded others during nuclear times. That should come as no surprise to a student of history even if many didn't expect Putin to in this particular instance.
But the pressing matter is would Putin use nukes? Would he use nukes if it means easy escalation to a mutual exchange where him and his country would end up as ash? Nah I don't believe he would unless some development allowed him to nuke with impunity.
Going after China would be magnitudes more painful than going after Russia. It would also hurt the US whereas Russia is mainly causing problems for Europe.