The difference being, if the ROC declares independence on a whim, the US will not intervene. This much I am absolutely 100% certain of. The PLA also happens to know this.
I feel like I disagree. Why would the US not intervene?
It's not the military or experts like you and your colleagues who decide, but the politicians. If the politicians order intervention, the military has to do it, no complaining about potential "disasters".
The military and experts might operate on "physical" realism, but politicians operate on "political" realism.
Politically, the US president and their party would get skewered alive (metaphorically) if they chose not to intervene at all. They HAVE to do something. Not even diplomatic/economic sanctions would be enough, military equipment aid like for Ukraine won't work for Taiwan (obviously), it has to be direct military intervention.
Politicians don't have to worry about the war hypothetically being a "disaster", their priority is to do whatever gets them the most support/loses them the least amount of support, that is, "political" realism. It's political unrealistic to abandon Taiwan even if Taiwan "triggers" a conflict by "declaring independence".
It's not the politicians job to explain properly to the people why they should or shouldn't get involved, they couldn't even if they wanted to. Emotions will be running high, I personally believe the situation will be like after 9/11, where overall broad support for decisive action will drown out anyone who disagrees. "If you don't want to intervene, you're a CCP shill/traitor/hate democracy" and so on.
I personally believe the politicians (the elite) at the top have a lot of power to make decisions. There's a limit to what they can realistically do, but if the "leader" makes an "official" decision, the fact that the decision is "official" will swing most people towards it.
Once the "official" decision to intervene is made, anymore who disagrees is attacked Goring style:
"We(democracy and liberalism and all the good in the world) are being attacked, the "pacifists"(panda huggers) are unpatriotic and are exposing our country to danger." and so on...
I feel it's more 50/50 than 100%.
The political leadership don't have to answer to the military officials and research experts who think its a "bad idea", they answer to the body politic (in the end, not necessarily in the beginning), and they can always find "yes men".
After the war, maybe a military official will write a book about how they warned politicians it was going to be "bad", but that's *if* things actually go "bad" for the US, and long after the decision was already made.
Maybe I'm wrong, but I feel my point is valid in that the decision to intervene will be primarily politically based and not "realism" analysis based.
P.S. I'm 100% sure there's at least one rep/senator? in the US (right now) who will vote no to intervention. I don't remember his name, but he's a *real* paleo-conservative. He voted no on the "Uygur Bill", for example.