My impression was that the most likely scenario was China blockading Taiwan until forcing a surrender. In that case, the US and its allies would have time to re

My impression was that the most likely scenario was China blockading Taiwan until forcing a surrender. In that case, the US and its allies would have time to respond although may be busy doing other things (eg responding to ships near Australia/NZ or Japan) Your situations seem possible but don't really cover any of the nuance of the real situation (see what China has been doing to the Philippines in the south china sea) A multiyear conflict with China would be difficult for the US. The manufacturing capacity and proximity would make a large category of aid difficult/impossible/useless. (Allies like SK or Japan could be more helpful in this situation)