rightly or wrongly, I'm quite confident the US will not go to war with China if it invades Taiwan - the American people simply wouldn't support it. It's one thing to get public support for dropping a few bombs on a tiny opponent with little risk, as the US regularly does, it's another entirely to go to war with a major power with a very high casualty rate. The US wouldn't have even entered WW2 (as much as the administration may have wanted to) if the Japanese hadn't foolishly attacked Pearl Harbor and then Germany declared war as well. But unlike Japan and Germany, China has the manufacturing capacity and access to raw resources that would make it a very different enemy.