> The agreement won't slow them much.

It absolutely will. They've been trying since 2013 to develop a cutting-edge indigenous semiconductor industry (the "Big Fund"), under fewer constraints, and haven't succeeded at anything but burning a lot of cash, by focusing on many of the "wrong" things (less fundamental science, chemical supply chain, and manufacturing equipment, more spent on value-add at far later stages of the manufacturing process, which has not helped them progress toward become self-reliant, but further deepened their reliance on the same players from Japan, Netherlands, the US, etc). This basically comes down to the fact that Chinese firms are extremely good at figuring out how to position themselves to take advantage of well-funded political priorities, like semiconductors were, and less good at.. uh.. doing the thing they say they're going to do. Many, many words have written about this subject, especially after the Gao Songtao was "disappeared" in a CCDI crackdown in 2021, and the government's financial commitment to the fund began wavering in January.

More constraints will certainly slow them down further, which is why the US did this. Frankly, if the US wanted to hurt them even more in this area, they absolutely could, and there have been numerous good suggestions for how they could severely restrict their access to even 5nm, 7nm and 14nm processes. I suspect the reason they haven't is more down to the fact that the US doesn't want to make this an "existential" issue for China, at least at this point.

My point is, it's not like theses sanctions flipped a switch, and now they'll start trying industrial espionage, or start "really for srs" trying to stop importing 90% of the value-add of their semiconductors. They've been stealing shit forever, it doesn't really put a dent in the fact that they just don't have the domestic expertise necessary to do this, or the economic or political environment to make it an achievable goal for them, even if the government makes it reeeeeally super clear to everyone that it is.

It's the same with lots of complex, high-tolerance electronics. If the US government woke up tomorrow and seriously set about the business of preventing China from accessing avionics, I doubt China would be able to build a modern airplane by themselves.