Look at a map of Taiwan. Or better, look at it in Google Earth. Taiwan is a narrow island with a mountain range running north-south down the middle. The developed areas are west of the mountains, facing China, in a strip 15 to 30km wide.

There's no defensive depth. And nowhere for all the people to go in an attack. It's not like Ukraine, where the current fighting is like battling over Iowa, one farm at a time. It's more like Gaza, with too many people crammed into too little land. But bigger.

China has a large number of truck-mounted anti-ship missiles. Bringing US Navy ships in the Taiwan strait means losing many of them. The PLAN has more ships than the US Navy, and is building more at a high rate.