Before any invasion of China there would need to be alot of preperation and things such as moving several carriers won't be possible to hide along with the mobilisation and deployment of troops into the region and i'm sure the Chinese war planners are working out every contingency just as the Americans are.
Any war will also cause alot of changed to the way people live as domestic GPS will probably be disabled and prices will rise as things like
clothing/new electronic gear start to become scarcer due to the factories are in China and i doubt the USA will allow enemy vessels to dock to unload
stuff just because some hipster wants a new iphone.
Theres alot of people of Chinese origin living in the USA so they'll need to be interned/fed for the duration like the Japanese in WW2 which will
place another burden on manpower/resources.
The main thing that will kill the USA's desire to goto war is that it won't be popular when they're shipping back corpses by the thousand.