So, I think what it is, is the US wants to create one of two results:

1. China backs down, they militarize Taiwan, turn it into an unsinkable aircraft carrier, turn the fascist reaction ideology dial up to 11 in the domestic propaganda and the anti-communism dial up to 12, hit them with that and try and create a situation where they can never peacefully re-integrate and are a permanent military outpost and bulwark as well as thorn in Beijing’s side.

2. They probably actually prefer this one. They push Beijing’s buttons enough and tip-toe over the red line that they react, they launch reunification by force. The US may or may not assist militarily, it doesn’t matter. Because the point isn’t to win against China militarily but to use the incident to create a Ukraine 2.0 situation of international liberal solidarity against China, to forcibly decouple anything resembling high-tech, slap embargoes on it, maybe even prevent Africa or Latin America from buying for example Huawei phones as part of sanctions they impose. This will be used to bully Europe and the rest of the world, by force, threat, and economic assault if necessary to decouple from China’s high tech, to strangle them diplomatically, trade-wise, etc. This will probably work for Europe who will fall right in line and suffer great pains to save the imperialist, anglo world capitalist order. They’ll probably follow this up with sanctions, high pressure, coups, etc against Africa, Latin America, rest of Asia to get them to fall in line. It really depends on how hard the global south resists but no matter what this would hurt China’s development and economy and buy the west time which is what they want.

A military loss to China over Taiwan is insignificant as while China can win in their neighborhood they don’t have the naval power to challenge and win against NATO far afield in say the middle east, Europe, etc where they can conduct interdiction and harassment of Chinese shipping to enforce a high-tech blockade. The real goal of 2 is to force liberals to back the fascist final struggle of capital against communism, to beat them over the head with the “democracy”, “liberal values” propaganda and sobbing.