E: accidentally posted empty reply
US won't leave JP/SKR/PH irrespective of TW, where they have token presence, and not integral to US east asia security architecture. That's really the broader security consideration, PRC doesn't want US in her backyard, PRC wants her own Munroe, and historically that involves forcing hegemon out / demonstrating their presense cannot be sustained.
JP/SKR nuclearizing more complex topic, e.g. it's against US interest since it erodes US control, forces PRC to build up ABM which is net bad for US strategic posture etc and imo makes PRC more likely to start pressing against US presence in region to turn up temperature knowing JP/SKR has higher chance to reduce US partnership if they feel comfortable with own nukes. Dynamics complicated, but I will just say nuclear powers like RU, and NKR, and eventually IR can still have their existence degraded via conventional means without raising to nuclear, and both those countries being import dependent islands (SKR functionally) are much more suspectible to conventional disruptions.
>convert economy
PRC exports to gdp 20%, about half to west, it's not _as_ domestic driven as US, but on export:gdp spectrum it's one of the least export led major economies. Export led is like >50%, TW/HK is like 60% and HK is like 200%. Most growth comes from internal consumption, exports help in geoeconomics, but numbers also go up stupid amounts in war economy.
>Except for TW, no one would lose more economically than the PRC if there is war.
Really depends on scale/scope of war. Taking out 95% leading edge TW semi effect on western tech hard to quantify in $$$ and capability terms, but it's not minor. Get JP/SKR involved, PRC's largest export competitor (electronics/cars etc) / regional influencer (JP FDI), and all of a sudden 1trillion+ per year in regional spoils open up. Open up mainland strikes = openning CONUS for retaliation, and PRC pursuing conventional global strike. And US by virtue of being reigning hegemon with most, also has most to lose. A lot of US hegemonic structures depend on CONUS serenity, which ended/ending with advanced rocketry. Think of what happens when US/PRC start trading energy infra, data warehouses, aviation plants, who has more global footprint to lose. Who has more people/excess capacity to reconstitute faster? Who really has most to lose, and what can be gained. Even phyric victory has a relative victor, and not all wounds heal the same. I think that's what missing from strategic thinking about TW scenarios involving US+co. For PRC, TW is most emotionally/politically important piece of US containment architecture. But JP/SKR/PH more strategically important. As long as US contains with forward posture, PRC will try to break containment. And I don't think US leaving without a fight.