Which suggests the US is unlikely to opt for another "quick and easy" operation, which would give them a similar level of casualties, in a much shorter period of time.Last time I checked the US provided most of Afghanistan's security for 20 years - longer than the Soviets - with thousands of US personnel killed and tens of thousands wounded. No one on this forum predicted the US staying so long.
China's military planning will almost certainly assume there will be a US response. The only question will be whether, in the event of an attack on Taiwan, the PLA attacks US bases first, or, to avoid a Pearl Harbour US political backlash, doesn't make a first strike and gives US forces time to respond.
If China makes a move of it's own volition, it would be at a time when the balance of power means the US is unable and unwilling to do anything. Hell, even as of a few years ago US wargames conceded that a US intervention that close to China would be suicidal.