This is a little outside my normal universe of discourse. However, I recently met with some high-level US intelligence professionals and we had [unclassified] conversations. These are my takeaways on the questions in the title.
Please comment or reach out to me privately if you have something to add.
The main three points to realize are that:
1) China wants political control of Taiwan. It “completes” their empire. They feel it “rightfully belongs” to them. This is not new.
2) Taiwan is unique in all the world in its manufacturing capability: all GPUs, high-end CPUS, and most flat panel displays are made there. Taiwan is like Arrakis and chips are like the spice if you know the reference. Neither the PRC or the West wants to destroy that capability. The entire AI industry and much of the the IT industry depends on Taiwan. (there are lessons to be learned here - but that’s another topic)
3) Given (2) above, neither the PRC nor the West want Taiwanese industry to be disabled or destroyed - any time soon. It would be disastrous for both - but arguably worse for the West. (Though the Yuddites might rejoice :-)
So, leaving aside the issue of Biden's mental/physical status for simplicity: the arguments I heard are that neither the PRC nor the West wants Taiwan to be a smoldering ruin. However, Taiwanese industry in ruins would hurt the West more than it would hurt China.
Thus, President Xi can simply say to POTUS (whoever that is) at any time in the next few years: “we are now taking control of Taiwan militarily and more importantly, politically. It is your choice whether your want to destroy Taiwan by counterattacking. If you counterattack, we ourselves might destroy the Taiwanese factories. Yes, that will hurt us, but it will hurt you more. Or you can leave things be: we get political control, and everyone gets chips and makes money”.
That way everyone (except the Taiwanese people) get what they want: The West and China get a functioning Taiwanese industry which they are both dependent on for AI and other high-end hardware, and from which they all make money. And the Taiwanese keep making money too, instead of suffering war, death, and damage.
On the other hand, if the Chinese wait too long (say > 5 years) the US can on-shore a lot of chip production for high end GPUs and such, then the window may close. So while I think "this month" is a little soon for a PLA military move on Taiwan, sometime within the next five years is the danger zone.
There are several other wildcards here:
1) Could the PLA actually succeed in an amphibious assault? Without suffering destruction of Taiwanese industry or serious military setbacks (like the Russians initially suffered in Ukraine)? Amphibious assault (PRC —> Taiwan) is more difficult than assault on a neighbor on your border that is only literally meters away, with direct roads and rail lines (Russia —> Ukraine). And it’s not like the PLA has seen a lot of combat recently.
2) Would the US Navy just turn tail and run because they are so afraid of Chinese missiles? Or are Chinese missiles specifically (and the PLA generally) paper tigers?
3) What would the Taiwanese people do? Would they fight in the streets? How many of them? (remember how it went down in Hong Kong). Would they sabotage the factories? Would the PRC care since that would hurt the West more than it would hurt the PRC?
4) Repeating: The taiwanese semiconductor industry is unique - all GPUs, high-end CPUS, and most flat panel displays are made there now. That was so dumb. Apparently the globalists were willing do anything to save a penny on the dollar and externalize real costs (like military protection and human rights). Or was it that “global trade makes military conflict obsolete”?
Nevertheless, the main supplier of the equipment in the Taiwanese factories that make the high the end chips is ASML. ASML is a Dutch company (it happens to be the most highly valued European company).
ASML, the Dutch government, the EU, or the US could shut down the supply chain for the chip-making machines in Taiwan and the Taiwanese high-end chip industry would subsequently shut down. But again, this is arguably worse for the West even though it would hurt the PRC too.
5) If hostilities between China and Taiwan broke out or were about to break out European and American managers, technicians, and lead engineers would not stay in Taiwan. This would also cause the Taiwanese chip industry to collapse. But again, this arguably hurts the west more than it hurts the PRC.
6) Would China be content having taken Taiwan or would this lead them to become more belligerent and try to expand to Vietnam etc? Arguably “no" since those people are in no way Chinese and those lands are not “a part of China”.
7) Japan is unlikely to sit idle if China makes a military move.
8) However, barring a collapse of the PRC (or if there is a US collapse) it is probable that there will be an eventual "Hong Kong-ization" of Taiwan. The question is, is it inevitable? Is it avoidable? and on what terms?
It is a complex chess game