ARM's products are predominantly IP and China has a famously lax attitude towards enforcing western-style IP laws.

China wouldn't need an import ban - just a ban on paying license fees.

That can work both directions. If China is going to disregard all US intellectual property rights, then the US can do the same to China (which is the world's largest manufacturer and has at least as much to lose as the US does over such an approach in the coming decades as they seek to move into high value manufacturing increasingly).

That means as China produces its first leading semiconductor products, US companies are free to reverse engineer them and immediately begin producing them (whether in Vietnam, Mexico, Taiwan, South Korea, India or Arizona and Texas), all without compensating China a dime.

As China begins producing its first leading pharma/biotech products, US companies are free to steal all IP from those companies and sell it as their own all around the world, with zero compensation to China.

And so on.

China is going to become the world's largest economy and will soon have the most to lose (if they don't already). Let's see how they like it when the tables are turned.

US has massive IP portfolio advantage, it will lose more. IP intensive sectors account for 1/3 of US GDP and affects as much employment. China is very far away from that and even if she creeps towards or surpass parity, these sectors will employ relatively smaller fraction of total population, i.e. it will affect Chinese society less - these nascent sectors may mature slower or not progress, versus US/west already heavily invested would actively regress. These scenarios have very different ramifications.

It's in both US/west and Chinese interests to maintain general IP racket and deal with sectors of exception. China is obviously not going to respect IP that it is willing to license if said denied via sanctions / geopolitical posturing. Just like military R&D, lack of access = valid rationale to espionage and undermine. West sanctions arms export to China after Tiananmen, now China has massive indigenous military industry. Semiconductors seems no different. Would have been better to draw out reliance on foreign hardware.

Escalating the tensions is not a solution; it just makes it harder down the road to find actual, workable solutions.

Bluntly put, do we want a trade war with China to go hot?

I think we do. They've had a very favored status for decades now. I didn't like a much of what Trump did, but playing hardball with China, I definitely liked that.

MIPS and RISC-V for CPUs; AMD, Intel, and others for PC and embedded GPUs.

China has already sunk in billions into RISC-V. So they are working on it. And it would not suspires me they will weaponise it against ARM.

The winner would be us, as we have more to choose from, and since RISC-V is open nothing much will stop non-Chinese manufacturers from also making their versions. We may see a reverse version of the familiar Chinese tech cloning in this case.