If the war becomes a war between US and China, then it becomes Great War 3.0. Then China will most likely not Invade Taiwan. It will focus on Defeating US first before spending its energy on a Taiwan invasion.
Instead of invading Taiwan, the focus will be destroying US forces in Okinawa, Guam and eventually invade those places if needed to stop US from using those places as a platform to attack China. For US also, stopping Taiwan invasion will be secondary. The main goal will be destroying China's military capability for good.
Which means striking Chinese forces in Sea, Air and Land and also destroying China's military production capacity, blockading China's trade to force China to capitulate into some kind of humiliating treaty that will curtail China's production. If they sense weakness, they will even hope to cause some kind of internal revolution that leads to CCP being forced out of power by a pro-US government or a civil war that causes China to be broken up into pieces.
China's goal will also be complete withdrawal of US forces from the first island Chain, Forcing some kind of regime change in Japan, Korea, Phillipines to have a pro-China government. Complete end of US influence in those countries followed by Chinese presence will be the larger goal.
If China manages to defeat US and destroy its capability and force them to withdraw only then they will think about invading Taiwan. But I think by then Taiwan will probably surrender without needing invasion. Entire basis of Taiwan's fighting will depends on Western Worship and US backing. If US itself withdraws, Taiwan will lose all will to fight.
So, lets not kid ourselves, this will not be a limited war. It will be a total war.
Let's not kid ourselves that the US would jump straight into WW3 with China the moment armed reunification begins. The US are some of the biggest cowards. They will never be the first to directly take on a powerful enemy with nukes. They will do what they had always been doing since WWI: let others fight and die to weaken the enemy first before the US steps in. If you have been observing all those American wargames, think tankers, and even military fiction writers. They always have the someone else fight the big bad enemy first. Then the US steps in to support the victims first, and when the enemy has been sufficiently weakened, then only the US finally joins the war to finish the job.
Here is my take on how the US plans for the Taiwan proxy war:
1) Taiwan provokes armed reunification with mainland China. China begins military operations.
2) The US and its allies are gonna throw the mother of all sanctions on China. Freeze China's financial assets in Western banks, and then steal them. The Republicans in particular would love this robbery. Because it means that the US could "cancel" the debt it owes to China by robbing China.
3) The US is gonna demand its allies in the region: Japan, SK, PH, and Australia to become the staging grounds for logistical aid to Taiwan. All will mobilize their navy and air force. They might push China's lines, but would refrain from getting into a direct shootout with China. They all want the Taiwanese separatists to be the ones to die bleeding the Chinese first. They might send mercenaries and volunteers, just like a familiar war we all know.
4) China predictably refrains from shooting at non-Taiwanese forces. The US and its allies will be comfortable to stay out of the war and conduct a de-facto naval blockade on China. Japan and SK will take the biggest risk, since their assets are within the first island chain. While the US and Australia will stay at the periphery of the first island chain to support from behind. In case the big war happens, Japan and SK will bear the brunt of the casualties first, and the more precious (white) American and Australian lives would still be able to stay out of range from the carnage.
5) The US will call on its "trump card" QUAD ally: India, to join forces to blockade China at the Malacca Straits. Not caring that this will also cripple the economies of ASEAN, Japan, and SK.
6) The US assumes that it can sustain a supply chain to Taiwan from the East of the island. They are betting that the Chinese won't recklessly fire on US and ally supply vessels going to Taiwan. The US hopes to supply the Taiwanese Bobas with Harpoons, Patriots, JASSMs, ATACMs, Tomahawks, and whatever weapons that they want to bleed China. Tomahawks in particular will be the Boba's favourite propaganda weapon to launch into mainland China and wreak havoc, while keeping America's hands clean. Bottom line is, no American lives shall be sacrificed if it can be helped.
This is the fictional scenario that the US hopes would play out:
1) The US would assume that the PLA are incompetent idiots who would crumble under the barrage of American Wunderwaffes used by the Taiwanese Bobas. The US would assume that PLAN, PLAAF, and PLA landing force would be severely depleted at this point. Coupled with the economic blockades, the US assumes that China would be on the verge of collapse. At almost no cost for American lives. This is the ideal war for America.
2) Once China is assumed to be on its knees. The US could now directly step in, pushing aside a crippled PLA, the US would do the shock and awe on a vulnerable China that it wet dreams about so much. Bombing a China that is on its knees until China begs the US for an unconditional surrender. The US and its allies would be victorious, and the US only pays the cost with Taiwanese lives and stolen Chinese money.
What I think would most likely happen is this:
1) The PLA are not the incompetent idiots the US and its allies assume them to be. There will be blunders, because it'll be the first time conducting a major high-intensity war. But they will learn from their mistakes very quickly.
2) The PLA will not be reckless and throw its forces like a human wave at Taiwan just for a political show of face. Their strikes on Taiwan will be methodical and calculated. The plan is to cripple the Taiwanese military first. Eliminate the navy, airforce, coastal defences, army, and its command and control. Any amphibious or airborne landings will take its time. There is no need to rush them in needlessly.
3) Any advanced Western weapons sent to Taiwan cannot be used effectively, because most of the Taiwanese military will not be sufficiently trained to use them. And what's stopping China from interdicting the ports of entry for arms sent by the US and its allies?
4) The Taiwanese Boba army will be grinded down while nervously waiting for that dreaded PLA amphibious landing.
5) China's economy will suffer from the mother of all sanctions, but China will go into a wartime economy mode. Most Chinese people will get into patriotic mode. They would bite the bullet and help their motherland to win the war. Traitors will be put to jail, or leave the nation for good. If there is any hint at how fast China can mobilize its economy into wartime mode, remember how China responded to the Covid emergency in Wuhan.
5) Without US or allied intervention, the Taiwan Boba army could be on the verge of crumbling once the PLA is ready to send an invasion force. They could surrender before the PLA arrives, or be routed when the PLA does arrive. Urban warfare would be ugly for both sides, but the PLA would eventually win with air and ISR superiority, and superior training. The DPP leadership could attempt to flee, but with the risk of interception by the PLAAF or PLAN.
Off course the elephant in the room is what if the US and its allies intervene? They could, and it would be WWIII. But it'll will cost them much more in blood and treasure than they will have ever anticipated. More realistically, they will try their hardest to avoid direct intervention and fight from behind Taiwan. The US have thrown many allies under the bus already. It won't have any qualms about throwing Taiwan under the bus. The main US objective in a Taiwan conflict is to give it the excuse to throw the mother of all sanctions at China, blockade China's sea lanes, and steal Chinese money in its banks. Essentially, to stop China's rise without risking American lives. It does sound crippling for China, but if the US does this, it would end the world economy as we know it. China will suffer, but it can still bite the bullet, fully import its raw materials by land, and produce the stuff it needs. The US will pretend to be strong and rich for awhile, but would soon realize that it has cash, but nothing to buy it with. The US can buy raw materials but it doesn't have the means of production to produce common items at scale outside of China. The real economy will eventually destroy the over-leveraged economies of the US and its allies. While China could still limp itself back into recovery.
