If they don't contain US technology then there is no part to sanction. If you mean through other channels such as canceling unrelated agreements or exerting political pressure, yes of course we can always expect the US to do that. They have already been doing that in persuading other countries to not buy Huawei. Doesn't mean it will always work, and every time the US tried it is draining its political capital. I get your concern that this could make it unreliable if part of the supply chain is completely dependent on a 3rd country, and it is important to get hold of core technologies at home, I agree.I agree with you for the most part on the process of de-Americanization of supply chains. There are huge incentives for countries like Japan and Korea to develop "Certified 100% America Free" technology products for the Chinese market - however, that assumes the US is willing to play by at least some rules and not sanction these countries for supplying advanced technology even if it contains no US components or IP whatsoever. Given the perfidy and thuggery we've seen from the US, there's no reason to assume any such restraint on its part. Hell, Japan faced sanctions in the '80s for developing such technology itself! Any objection that that would be against the law (whose law?) is futile. The US is dying and it's determined to play Samson and pull the temple down on itself and everyone else, that's just a fact. Therefore, there must be total Chinese self-reliance (not just that, but world leadership) in core technologies like semiconductors no matter what it takes.
We know that the domestic DUV (immersed) machine is not yet ready. Rumor says it will begin production testing next year, let's say it will be delivered early by 2nd half of 2020, setting it up, passing test production, working out all the bugs, making it commercially viable for 28nm production, and then push towards 14nm, as well as making enough machines to fulfill capacity......even if they didn't encounter any big obstacle, these will still take time. I can't (and I didn't) say exactly how long, but if all these only took 2 years I'd be more than happy.I also want to question you a little on your timelines for DUV and EUV introduction. You say it'll take time for the first commercial Chinese DUV machine to reach 14nm (even 28nm), let alone 7nm. Ordinarily I would agree, given the lackadaisical pace of Chinese research in lithography prior to US sanctions, but now I simply cannot see anything but a full-on war emergency effort to get this technology to the cutting edge. It would be a mistake for Chinese DUV to spend a day at 28nm - straight to 14nm and in months transition to 7nm. As for EUV, I'm not exactly sure what the Changchun Institute announcement in 2017 is about, but if it's a complete tech demonstrator then I expect the first generation of commercial machines to appear, J-20 like, in the next year or two (or three, just to cover my rear).
For these kind of projects you have to take the scientific approach, trial and error takes time, knowledge accumulation takes time, training people takes time, throwing money at it can't accelerate this process proportionally. Skipping steps could also make you lose more time instead of gaining it.