To do that they need to have ASML, Canon and Nikon all stop shipping immersion lithography tools to all of China.
That is much more difficult than stopping TSMC from shipping to Huawei.
On other hand, lots of optics in steppers come from China. Zeiss is still the king for the biggest, and highest spec lenses, but Chinese optics companies pushed them out of all, but that niche. Even Zeiss itself makes a lot of lenses for top tier equipment in China.
Lots of other hard to replace stuff in litho equipment is made in China. From specialty ceramics, to high spec nuts, and bolts. Precision casting, and machining of lots of parts for American equipment is done in China as well.
Arm twisting, for arm twisting, we can shut down the semi equipment industry for a few years.
We can't talk with them seriously without making them hurt. With each passing day, we make it easier for them to walk away from that with little cost.
I don't see Chinese diplomacy putting any effort now to come out of all of this, if not as a winner, then not a complete loser. It is this inaction that only invites more hostile actions.
Now, take a look how Hu's administration handled the hostilities a decade ago. Even such insignificant bargain piece as REE exports worked excellently at shutting the opposition down within days, when it was employed at day one, and without any mixed signals. The West had all incentives to try to weather the embargo, yet they didn't do s**t, because they believed that Hu was serious, and they will loose more political capital from that than they gain. The West after all also have cheap, and weak politicians, with their own fears that can be played.
Doing a retaliation along this lines is a 100% necessary step, and the only option left that will prevent further hostilities, and let us continue making money.
How it will work with regards to particular issue of semi industry? The semi industry is a truly international industry, and major participant in it can shut down the entire industry for months, and years. It is a very fragile industry, with many essential pieces to it being made by a one single vendor in existence. Deciding to divide the industry on American industry, and Chinese industry will break the industry.
Allowing USA to effectively shut down the semi industry for us with catastrophic impact, and keep it working for themselves should not let be, even if we can't hurt them as much as they can hurt us.